Ethics Opinions from the Bar Association of San Francisco
If an attorney in the process of discovery in a civil case finds that the opposing party may have engaged in tax fraud, he is not ethically barred from reporting it, unless he does so solely to obtain an advantage in a civil matter.
Does an attorney who during the process of discovery in a civil case, finds that the opposing party may have engaged in tax fraud, have a duty to report his finding to the appropriate tax authorities.
A lawyer is not ethically barred from reporting suspected violations of law by the opposing party in a lawsuit.
The information discovered by an attorney from the files of his opponent, if not protected by a court order or by other Stipulation between counsel, is unprivileged. While Canon 37 of the Canons of Professional Ethics of the American Bar Association provides that a lawyer has a duty to preserve the confidences of his client, no similar protection is provided for communication from an opponent. Thus, the issue involved here is whether an attorney who comes into possession of unprivileged information concerning the possible commission of a crime may report his findings to the proper authorities.
A similar issue was considered in ABA Informal Opinion No. 1210, 2/9/72. The Committee there was asked to decide whether a disciplinary authority of a state Bar Association could transmit unprivileged knowledge of the commission of a crime by an attorney. Concluding that the board should report the information, the committee relied upon DR 1-103 of the Code of Professional Responsibility which provides: "A lawyer possessing unprivileged knowledge of violation of DR 1-102 shall report such knowledge to a tribunal or authority empowered to investigate or act upon such violation." 
The Committee did not limit its opinion to criminal conduct of lawyers. Noting that DR 7-102 which provides that a lawyer who receives information that establishes "a person other than his client" has perpetrated a fraud upon a tribunal must report his findings, the committee recognized that apart from such considerations a lawyer has the duty as a good citizen to aid in the enforcement of criminal laws and to report unprivileged knowledge of criminal conduct to appropriate authorities.
Other Bar Committees have reached like results. For instance, the Committee on Professional Ethics of the Association of the Bar of the City of New York found in Opinion 265, March 30, 1933 that an attorney who was given certain papers of a corporation by one of its officers, who was not a client of the attorney, should deliver the papers to proper authorities when they reveal the perpetration of a crime by some of the officers of the corporation. Likewise, the Committee on Professional Ethics of the New York County Lawyers Association in Opinion 339, 1936, concluded that there is no ethical bar to an attorney's revealing to the public violations of state law by the state's administrative body which he serves as counsel. Finally, in Opinion 82 of the ABA Formal Opinions (December 2, 1932), the committee concluded that an attorney who obtains information in the course of a trial that a corporation, not his client, and others not connected with the action are evading tax payments may report this information to the authorities.
Under the principles considered in these opinions, while an attorney may not be legally bound to disclose his findings to the authorities, there is little doubt that he is not ethically barred from making a report.
All opinions of the Committee are subject to the following disclaimer:
Opinions rendered by the Ethics Committee are an uncompensated service of The Bar Association of San Francisco. Opinions are advisory only, and no liability whatsoever is assumed by the Committee or The Bar Association of San Francisco in rendering such opinions, and the opinions are relied upon at the risk of the user thereof. Opinions of the Committee are not binding in any manner upon the State Bar of California, the Board of Governors, any disciplinary committee, The Bar Association of San Francisco, or the individual members of the Ethics Committee.
In using these opinions you should be aware that subsequent judicial opinions and revised rules of professional conduct may have dealt with the areas covered by these ethics opinions.