120. A lawyer must not communicate in a matter with a person whom he knows to be represented by a lawyer, except in the presence or with the consent of that lawyer or unless he is authorized to do so by law. In the event of an unsolicited or accidental communication, the lawyer must promptly inform the person’s lawyer of the circumstances and content of the communication.
Subject to the first paragraph, a lawyer may seek information from any potential witness, but he must disclose the interests of the person for whom he is acting.