Court filings released on Monday show that federal prosecutors investigating President Trump's former personal attorney Michael Cohen have access to 12 audio recordings seized by the FBI during their April raid of Cohen’s office and hotel room in New York.

Timing: Trump attorney Rudy Giuliani confirmed Friday that Cohen had secretly recorded a conversation with Trump in September 2016, during which the two discussed a potential payment to former Playboy model Karen McDougal, who claims she had an affair with Trump.

The details: The McDougal recording is one of the 12 audio recordings referenced in the court filing, a sourced told CNN. It's also reportedly the only one that contains a conversation between Cohen and Trump. The filing did not say who recorded the 11 tapes nor what the other tapes picked up.

• The recordings were among the seized items submitted to a court-appointed special master for attorney-client privilege consideration, who then turned them over to federal prosecutors on Friday.

What they're saying: A source familiar with Cohen's legal strategy told NBC News that an attorney recording a client is not illegal. "New York is a one-party state. Taping a conversation is the functional equivalent of retaining notes," the source said.

Go deeper: Michael Cohen, the problem Trump can’t make vanish