Avenatti hasn’t yet acted on multiple requests from federal prosecutors in Manhattan for Clifford to waive the attorney-client privilege that prevents her former lawyer from discussing their communications about the nondisclosure deal, the people familiar with the matter said. In April, Avenatti, acting in his capacity as Clifford’s current lawyer, sent a cease-and-desist letter to her former lawyer, Keith Davidson, ordering him not to disclose any communications related to her, one of those people said.

Avenatti made similar demands of Clifford’s former manager, Gina Rodriguez, who helped engineer the hush-money deal. Avenatti tried to block Rodriguez from providing her communications with Clifford to federal prosecutors until he had reviewed them, other people familiar with the matter said.

Avenatti has told federal prosecutors he is trying to get Clifford to agree to waive her attorney-client privilege, but prosecutors have come to believe he is stringing them along, the people familiar with the matter said. The delays in responding to their requests to waive privilege aren’t seen as highly damaging to the probe but have frustrated investigators, they said.