(CNN) The FBI seized recordings President Donald Trump's attorney made of his conversations with a lawyer representing two women who had alleged affairs with Trump, a source familiar with the matter tells CNN.

The recordings could prove valuable to the government's criminal investigation of Michael Cohen. The President's personal attorney is under scrutiny in part for his role in seeking to suppress the alleged affair through a hush deal with porn star Stormy Daniels. The warrant sought information about that payment along with any information that connected Cohen with efforts to suppress disclosure of Trump's alleged affair with Playboy model Karen McDougal.

The warrant for the raids also specified that Cohen was being investigated for bank fraud, wire fraud and campaign finance issues, CNN reported earlier this week.

While Cohen has admitted to no wrongdoing, the intensity of the government's investigation will put significant pressure on one of the President's closest confidants. If Cohen chooses to cooperate rather than fight a potential case against him, then his knowledge about the President's activities could create serious problems for Trump as special counsel Robert Mueller continues his investigation.

The source said Cohen recorded some calls he had with attorney Keith Davidson, who at the time represented both Daniels and McDougal. Davidson no longer represents either woman. Their deals to keep their stories about alleged affairs quiet are now the subject of litigation, with each seeking to be released from their agreements.