We review three questions based upon three assignments of error brought forward by defendant: (I) whether the trial court committed prejudicial error by failing to dismiss the indictment that was allegedly based on perjured testimony; (II) whether the court erred in its instructions that the jury could find defendant guilty of conspiracy by finding an agreement between him and at least one other person, without identifying specifically the co-conspirator named in the indictment; and (III) whether the court erred in allowing the State to introduce evidence of allegedly per-jurious grand jury testimony of defendant’s co-conspirator.
I.
[1] Defendant’s first argument is that the trial court erred in denying his motion to dismiss the indictment on the grounds that it was based upon allegedly perjured testimony. On motion of the defendant, the trial court may dismiss an indictment if it determines that:
(1) There is ground for a challenge to the array,
(2) The requisite number of qualified grand jurors did not concur in finding the indictment, or
*42(3) All of the witnesses before the grand jury on the bill of indictment were incompetent to testify.
N.C. Gen. Stat. § 15A-955 (1988). Assuming arguendo that the testimony was perjured and that it would render a grand jury witness incompetent to testify within the meaning of subsection (3), we cannot say, based upon the record before us, that this satisfies the requirement that “all of the witnesses” were incompetent to testify before the grand jury.
Furthermore, defendant’s reliance on United States v. Basurto, 497 F.2d 781, 785 (1974), for the proposition that the prosecutor has a duty “not to permit a person to stand trial when he knows that perjury permeates the indictment” is subject to the same problem. Without knowing what other evidence was before the grand jury, we cannot determine whether perjury permeated the indictment.
Finally, we also reject defendant’s argument on the basis that his motion to dismiss the indictment, made at trial, was not timely. See N.C. Gen. Stat. §§ 15A-952(b)(4) (Supp. 1992), 15A-955 (1988); State v. Phillips, 297 N.C. 600, 605-06, 256 S.E.2d 212, 215 (1979).
II.
[2] Defendant’s argument that the trial court erred in instructing the jury that they could find the defendant guilty of conspiracy without limiting the conspiracy to one with the co-conspirator (Branch) named in the indictment has merit.
The instruction about which defendant complains included a statement that, “if you find from the evidence and beyond a reasonable doubt that on or about the alleged date that the defendant agreed with at least one other person ... [to commit the offense] and that the defendant and at least one other person intended at the time the agreement was made that it would be carried out, then it would be your duty to return a verdict of guilty . . . .” (Emphasis added). The trial court used this language to instruct the jury on the offense for which defendant was indicted and on the lesser included offense for which defendant was convicted.
The North Carolina Constitution provides that “in all criminal prosecutions every man has the right to be informed of the accusation” against him. N.C. Const. Art. I, sec. 23. In State v. Mickey, 207 N.C. 608, 178 S.E. 220 (1935), the Supreme Court dealt with *43a similar situation in which the defendant was indicted for conspiracy with two named co-conspirators to commit murder. In its charge, the trial court instructed the jury that it might find the defendant guilty if it found that he had conspired with both co-conspirators or others. The Supreme Court held that this charge put the defendant on trial for an offense additional to that named in the bill of indictment and ordered a new trial.
We believe that this case controls our decision. The evidence in this case, as in Mickey, tends to show that defendant may have conspired with a number of persons, not just the named co-conspirator, to commit an unlawful act. Consistent with Mickey, this Court has also examined the charge as a whole to determine whether the error was cured. We cannot find that it was. Consequently, we must order a new trial.
Finally, because one of the additional issues brought forward by defendant is likely to be raised at his second trial, we must address it in this opinion.
III.
[3] Defendant assigns error to the trial court’s allowing the State to introduce, for impeachment purposes, the grand jury testimony of the alleged co-conspirator, Branch. The record reflects that on the day before trial Branch stated his intention not to testify at the trial. Prior to Branch’s testimony before the jury, the trial court allowed a voir dire examination of Branch, and we quote from the prosecutor’s examination the following excerpt:
Q. . . . [W]hat did you tell . . . [defendant’s attorney]?
A. I told him that detective had seen me, had brought me in an office up here, and he was trying to make some kind of deals with me about early release from prison if I would testify against Minter.
Q. And what did you tell him?
A. I told him I couldn’t do anything like that because I don’t know really what they talking about and I already have my time. You know. That’s a relative of mine. I couldn’t testify against him.
Q. And you told . . . [defendant’s attorney] that yesterday?
A. Yes.
*44Q. You couldn’t testify against him?
A. Yes.
Q. And is that your position now? You’re not going to testify against him?
A. No, sir, I’m not.
Q. . . . Are you going to tell the truth about your dealings with Mr. Minter back here in 1989 and ’90?
A. Yes, I am.
Q. Is that the same thing you told the grand jury?
A. Yes.
Whatever you-all got on that document from the last time I was here in the grand jury, like you read it to me yesterday, all of it is not correct.
Q. What you’re saying is that what you told the grand jury wasn’t correct?
A. Not most of it.
Q. Most of it is not correct?
A. No, it’s not.
Q. You mean you lied to the grand jury?
A. No. I didn’t lie to them.
Q. Well, what happened? It was taken down wrong?
A. I believe so.
Shortly after this questioning, the trial judge interrupted to advise Branch about perjury and to appoint an attorney to represent him.
During Branch’s testimony in the presence of the jury, Branch initially claimed that he could not “recall right offhand” if he told Detective Pendergrass that he had brought defendant to North Carolina to help him sell drugs. He did, however, deny making such a statement before the grand jury. After defense counsel’s objection to the prosecutor’s questions about his prior testimony *45that defendant shot another man over drugs, Branch stated, “I’ll be willing to accept the facts and the punishment for false perjury. May I step down?” At the prosecutor’s request, the trial court declared Branch an adverse witness.
To many of the later questions concerning his testimony about defendant before the grand jury, Branch responded “[f]alse testimony.” Over defendant’s objections, the prosecutor was able to recapitulate most of Branch’s grand jury testimony through this questioning. The trial court later allowed the introduction of that portion of the grand jury transcript that recorded Branch’s earlier testimony.
After the close of the evidence, and with the jury excused from the courtroom, Branch pleaded guilty to perjury. During the acceptance of his plea, the trial court asked Branch if there was anything he wanted to say, and Branch responded:
Defendant Branch: Yes. It wasn’t no lie.
The COURT: What do you mean it wasn’t any lie? You said it was a lie?
DEFENDANT BRANCH: I’m saying, you don’t know the whole facts. That’s all I’m going to say.
The COURT: Oh. Well, what are you talking about? I don’t understand what you’re getting at? Stand up so I can understand you better.
Defendant Branch: See, it wasn’t no lie.
THE COURT: What are you talking about? I don’t understand?
DEFENDANT Branch: That you just made your comment on. I told a lie.
THE COURT: Yes. You said you did.
Defendant Branch: It wasn’t no lie.
The COURT: I’m just going by what you said yesterday under oath.
DEFENDANT Branch: You don’t know — what I’m trying to express tó you, you don’t know the situation and the whole facts. The situation, the predicament that I am in.
*46THE COURT: Well, I’ve got an open ear. I’ll hear whatever you want to tell me.
Defendant Branch: That’s it.
The Court: ....
Now you went before the grand jury under oath. At the time, as I understand it, you were in prison then; is that right?
Defendant Branch: Yes.
THE COURT: And you took the oath to tell the truth and gave testimony. Yesterday, you took the oath and gave testimony. Of which you affirmed a notion that you gave false testimony before the grand jury is what you said.
DEFENDANT Branch: See, when I came here in front of the grand jury, I wasn’t notified that — who I was coming here before the grand jury. I was coming here for what I know of Richardson. I didn’t know I was coming for Minter.
THE COURT: In other words, you tell it one way for Richardson and another way for Minter?
Defendant BRANCH: No, I didn’t. They asked me a few questions and I told them what I, you know — I told them what dealings I had with Richardson. I didn’t know I was supposed to come to court here to be no state witness. Work for no state. It wasn’t no charges brought up on me.
THE COURT: Well, you got one now. Which is totally self-inflicted. You worked hard to earn this charge and about as clearcut case as I’ve seen lately. Just worked your way right into it. I tried to warn you about the law. You had a lawyer appointed to tell you how important it is to tell the truth. If I didn’t know the difference, I’d put money on the table saying that you are protecting somebody. Something has happened to you as a witness.
Defendant Branch: I’m protecting my family.
THE COURT: Well, there’s something going on here that’s changed you around. And I’d like to know who it is that you are relying on to change your testimony. You’re not going to tell me that, are you?
Defendant Branch: My family.
*47The COURT: Has somebody threatened you?
Defendant Branch: Yes.
THE COURT: Has somebody told you to change your testimony?
DEFENDANT BRANCH: In a way. Yes. It have not been Minter. Have not been Richardson. I was threatened in prison.
The COURT: Well, you told your lawyer you can deal with this perjury charge, didn’t you?
Defendant Branch-. Yes, I can.
THE COURT: Well —
Defendant Branch: I also was wounded.
THE COURT: What’s that?
DEFENDANT Branch: I also was wounded by their behalf.
The circumstances surrounding witness Branch’s plea to the charge of perjury provide meaningful insight into that plea. We believe that the extraordinary facts of the case require us to reject defendant’s argument that the court erred in allowing the State to introduce evidence of Branch’s grand jury testimony.
In N.C. Gen. Stat. § 15A-623(e) (1988), the General Assembly mandated secrecy for grand jury proceedings and, “except as expressly provided in this Article, members of the grand jury and all persons present during its sessions shall keep its secrets and refrain from disclosing anything which transpires during any of its sessions.” Subsection (h) of the same statute provides, among other things: *48N.C.G.S. § 15A-623(h). This statute implicitly leaves to the jury the determination of whether the witness is being honest in his testimony before them. (It is noteworthy that, in 1991, the legislature changed the quoted sentence in subsection (h) to omit the phrase “to corroborate or impeach that witness,” suggesting that such testimony may now be introduced as substantive evidence. The effective date of that change, however, was after defendant’s trial, and its effect is not before us.)
*47Notwithstanding subsection (e) of this section, the record of the examination of witnesses shall be made available to the examining prosecutor, and he may disclose contents of the record to other investigative or law enforcement officers, the witness or his attorney to the extent that the disclosure is appropriate to the proper performance of his official duties. The record of the examination of a witness may be used in a trial to corroborate or impeach that witness to the extent that it is relevant and otherwise admissible.
*48In contrast to this statute concerning sworn grand jury statements, the cases cited by defendant and other cases cited in the concurring opinion all pertain to unsworn statements of witnesses and, therefore, are distinguishable on this basis, and, in some instances, additional bases. The evidence the State sought to introduce in State v. Hunt, 324 N.C. 343, 378 S.E.2d 754 (1989), was unsworn testimony of a 14-year-old prostitute who denied even making a previous statement. Likewise, in State v. Williams, 322 N.C. 452, 368 S.E.2d 624 (1988), the Supreme Court refused to allow the State to impeach a witness by using his prior unsworn statement which itself constituted hearsay. Williams also involved the witness’s denial that he had ever made a prior statement. In State v. Cutshall, 278 N.C. 334, 180 S.E.2d 745 (1971), the Court held inadmissible an earlier unsworn statement of defendant’s son, finding the statement a “speculative, conjectural expression of opinion completely lacking in probative value towards establishing a material fact in the case.” Id. at 349, 180 S.E.2d at 754-55. Again in Cutshall, the Court dealt with the State’s attempt to elicit evidence of a statement after the witness denied making it. The case of State v. Moore, 275 N.C. 198, 166 S.E.2d 652 (1969), like Williams, involved double hearsay. The Supreme Court held that a witness’s prior unsworn statement about what the defendant had told him was incompetent. The statement was collateral because at trial the witness denied ever making it.
Relying on Hunt and Williams, the Court of Appeals determined in State v. Jerrells, 98 N.C. App. 318, 390 S.E.2d 722, disc. review denied, 326 N.C. 802, 393 S.E.2d 901 (1990), that the State could not introduce evidence of a prior unsworn statement by a witness who at trial denied making the statement.
All of these cases dealing with the admittedly complex question of collateral matters stand for the proposition that, once a witness denies having made a statement, the State may not impeach that *49denial by introducing evidence of the statement. While the case before us contains some instances in which the witness Branch denied making certain statements before the grand jury, in many other instances, he claimed that statements he made were false.
We believe that once Branch refused to testify or claimed that parts of his earlier, sworn statements before the grand jury were false, the State’s use of that testimony was proper for impeachment purposes. It called into question his denial that he had conspired with defendant to traffic in cocaine, and it therefore went to the essence of, and was material to, the State’s case. After hearing arguments of counsel, the trial judge made appropriate findings of fact and concluded that the testimony was admissible for impeachment purposes. At the time the transcript was admitted, he correctly instructed the jury about its limited purpose. We hold that, under this set of facts and given the statute cited above, the trial court properly allowed the introduction of this evidence.
We also disagree with defendant’s related argument that the prosecutor acted in bad faith in introducing the transcript of Branch’s grand jury testimony. From the record, one cannot tell that either the prosecutor or counsel for defendant was aware of N.C..G.S. § 15A-623(h) which limited the purpose for which the grand jury transcript could be introduced. Indeed, their arguments hinged on State v. Hunt which actually supports the prosecutor’s actions.
In Hunt, the Court looked to federal cases for guidance in discerning those rare instances when the State’s introduction of prior inconsistent statements by its own witness was not made solely for the purpose of putting the substance of the statements before the jury, and was not a mere subterfuge. Such exceptional circumstances include “the facts that the witness’s testimony was extensive and vital to the government’s case, that the party calling the witness was genuinely surprised by his reversal, or that the trial court followed the introduction of the statement with an effective limiting instruction.” Hunt, 324 N.C. at 350, 378 S.E.2d at 758 (citations omitted). After concluding that there was no assurance that the witness’s testimony was critical to the State’s case or that it was introduced altogether in good faith and followed by effective limiting instructions, Id. at 351, 378 S.E.2d at 758-59, the Court found that the witness’s prior unsworn statement was inadmissible. In this case, however, Branch’s testimony could hardly *50be more critical to the State’s case. The record reflects that the prosecutor was made aware the day before trial that the witness had indicated his intention not to testify against the defendant. The prosecutor, however, had no choice but to call this witness. We believe that this is one of those rare instances in which the State’s introduction of a prior inconsistent statement by its own witness was not a mere subterfuge.
Moreover, in light of the 1991 change in the statute, we cannot see that the prosecutor argued for an unreasonable extension of the law.
For the reasons set forth in section II, we hold that defendant must be granted a
New trial.
Chief Judge ARNOLD concurs.
Judge GREENE concurs in the result with separate opinion.