In a recent case, Connecticut Supreme Court considered "whether a prosecutor’s intrusion into communications between a defendant and his attorney that are subject to the attorney-client privilege requires the dismissal of the criminal charges against the defendant." Finding that the prosecutor came into possession of and read certain written materials belonging to the defendant that were subject to the attorney-client privilege, the court reversed the conviction - which was obtained after the lower court had denied a motion to dismiss the charges based on the prosecutor's conduct. Interestingly, the court held that the conviction should be reversed regardless of whether the prosecutor's conduct was intentional. The opinion was not unanimous. You can read the opinion here. You can read the dissenting opinion here.
Thanks to the legal profession blog for the information.