Suppose that night before a hearing is supposed to start, the mother of a criminal defense attorney tells the attorney that her son (the client) is not going to show up. Then, when the judge notices the defendant is missing, the judge asks the lawyer where the client is or whether the lawyer knows why the client is not there. What should he lawyer do?
A short ethics opinion by the San Diego County Bar Association concludes that, under the California Rules of Professional Conduct, the attorney can't do anything. The attorney simply can't answer the judge’s question. If the attorney says she does not know, she is being dishonest with the court in violation of her duty of candor, and if she discloses the information provided by the mother, the attorney would be in violation of her duty of confidentiality.
Thus, the only proper response by the attorney would be that she can't answer the question. The Opinion (SDCBA Legal Ethics Opinion 2011-1) is available here.
Thanks to the Legal Profession blog for the link.