US President Donald Trump on Saturday said his ex-lawyer Michael Cohen may have acted illegally after it emerged he had secretly taped a discussion about payments to a former Playboy model over an alleged affair.
In Trump's first direct reaction to a report broken by the New York Times a day earlier, he added in a Twitter post: "The good news is that your favourite President did nothing wrong!"
The Times reported the FBI had seized the recording during a raid on Cohen's office earlier this year, quoting lawyers and others familiar with the recording. Cohen has not yet been arrested or charged.
"Inconceivable that the government would break into a lawyer's office (early in the morning) - almost unheard of," Trump tweeted.
"Even more inconceivable that a lawyer would tape a client - totally unheard of & perhaps illegal."
Former Playboy model Karen McDougal claims she had a months-long affair with Trump after they met in 2006, shortly after Trump's wife Melania gave birth to their son Barron.
She told CNN previously that he tried to pay her for sex.
The Wall Street Journal said the September 2016 conversation between Trump and Cohen was about buying the rights to McDougal's story, which she had sold a month earlier to The National Enquirer for $150,000.
The tabloid ultimately sat on the story, preventing it from becoming public.
The chairman of its parent company, American Media, is a friend of Trump's.
Friday's reports raised questions about why Trump's campaign denied knowledge of the deal between McDougal and American Media when it became public, and they fanned speculation about how much damage Cohen might be able to inflict on the president.
Trump's current personal attorney, Rudy Giuliani, had confirmed to the Times that the Cohen tape existed, but said it showed the president had done nothing wrong.
Regarding Trump's claim of potential illegality, New York state law permits the recording of a phone call or an in-person conversation as long as one party consents, according to attorney John B. Harris, who authored an article on the subject for the New York Legal Ethics Reporter.
Yet "it remains murky whether and when a New York lawyer can ethically tape without advance disclosure", Harris said.
He cited two recent cases that show "despite the burgeoning use of surreptitious recordings by members of the public, there is little tolerance for lawyers who - albeit legally - surreptitiously record" other parties without justification.
The FBI raided Cohen's home and office in April on a referral from special counsel Robert Mueller, who is looking into Russian interference in the 2016 election and whether the Trump campaign colluded with Moscow.
The Justice Department says Cohen has been under investigation for months for criminal conduct largely centred on his personal business dealings.
Prosecutors are apparently interested in payments he made on Trump's behalf to porn actress Stormy Daniels, and other business dealings related to Trump.
Both Daniels and McDougal allege they had affairs with Trump around the same time, in 2006.
Cohen, who became Trump's personal lawyer in 2007, is infamous for paying $130,000 to Daniels — real name, Stephanie Clifford — shortly before the 2016 election to keep quiet about her alleged affair with Trump.
Her lawyer, Michael Avenatti, claimed Friday there were "multiple" tapes and urged Cohen to release all audio recordings publicly.
"All of them should be released for the benefit of the American public," he told CNN.
"This is the tip of the iceberg," he added. "When all of this evidence ultimately comes to light, and I hope that it will... this is going to spell a significant problem for Michael Cohen and a larger problem for the president."