Final answer:
After formally representing a client, an investigator or lawyer shall not share confidential information obtained during that representation, in accordance with legal ethics and the duty of confidentiality integral to the attorney-client relationship.
Step-by-step explanation:
The question relates to professional conduct in legal representation. An investigator, also assuming the role of a lawyer who has represented a client, is ethically and legally obligated to maintain certain standards even after the representation has concluded. Specifically, the investigator/lawyer should not engage in the unethical practice of sharing confidential information obtained during the prior representation. This obligation stems from the duty of confidentiality which is fundamental to the attorney-client relationship. Such standards are rooted in legal ethics to maintain the integrity of the legal profession and the protection of clients' rights.
The scenario described does not include the prohibition against representing the client in other matters or receiving payment for services rendered, as these are normal aspects of a lawyer's professional engagement. Seeking legal advice from another attorney is also a permissible and often necessary aspect of legal practice. The core principle empasized here, in the context of legal ethics and the right to an attorney, is the safeguarding of confidential information.