(a) A lawyer shall not knowingly:
(1) make a false statement of material fact or law to a tribunal;
(2) fail to disclose a material fact to a tribunal when disclosure is necessary to avoid assisting a criminal or fraudulent act by the client;
(3) fail to disclose to the tribunal legal authority in the controlling jurisdiction known to the lawyer to be directly adverse to the position of the client and not disclosed by opposing counsel; or
(4) offer evidence that the lawyer knows to be false. If a lawyer has offered material evidence and comes to know of its falsity, the lawyer shall take reasonable remedial measures.
(b) The duties stated in paragraph (a) continue to the conclusion of the proceeding, and apply even if compliance requires disclosure of information otherwise protected by Rule 1.6.
(c) A lawyer may refuse to offer evidence that the lawyer reasonably believes is false.
(d) In an ex parte proceeding, a lawyer shall inform the tribunal of all material facts known to the lawyer which will enable the tribunal to make an informed decision, whether or not the facts are adverse.
If perjured testimony or false evidence has been offered, the advocate's proper course ordinarily is to remonstrate with the client confidentially. If that fails, the advocate should seek to withdraw if that will remedy the situation. If withdrawal will not remedy the situation or is impossible, the advocate should make disclosure to the court. It is for the court then to determine what should be done -- making a statement about the matter to the trier of fact, ordering a mistrial or perhaps nothing. If the false testimony was that of the client, the client may controvert the lawyer's version of their communication when the lawyer discloses the situation to the court. If there is an issue whether the client has committed perjury, the lawyer cannot represent the client in resolution of the issue, and a mistrial may be unavoidable. An unscrupulous client might in this way attempt to produce a series of mistrials and thus escape prosecution. However, a second such encounter could be construed as a deliberate abuse of the right to counsel and as such a waiver of the right to further representation.