President Donald Trump's lawyer Rudy Giuliani on Saturday said any attorney-client privilege claim over a recording of a phone call between Trump and former lawyer Michael Cohen has been waived, meaning federal prosecutors in Manhattan and the FBI can hear the tape, NBC News reports.

"It was already out there so seemed no point in objecting except on principle," Giuliani said.

"Nothing in that conversation suggests that [Trump] had any knowledge of it in advance. In the big scheme of things, it's powerful exculpatory evidence."

Cohen had taped a conversation two months before the 2016 presidential election with Trump concerning payments to a former Playboy model who said she had an affair with the Republican nominee. Trump on Saturday said the action was "perhaps illegal," but denied any wrongdoing on his part.

"Inconceivable that the government would break into a lawyer's office (early in the morning) - almost unheard of," the president tweeted. "Even more inconceivable that a lawyer would tape a client - totally unheard of & perhaps illegal. The good news is that your favorite President did nothing wrong!"

Inconceivable that the government would break into a lawyer’s office (early in the morning) - almost unheard of. Even more inconceivable that a lawyer would tape a client - totally unheard of & perhaps illegal. The good news is that your favorite President did nothing wrong! — Donald J. Trump (@realDonaldTrump) July 21, 2018

Cohen, whose office was raided by the FBI in April, is under investigation by federal prosecutors in Manhattan for his role in paying porn star Stormy Daniels $130,000 before the election to keep her quiet about an affair she alleged to have with the then-presidential candidate. Prosecutors are also probing alleged violations of election law and possible financial crimes associated with Cohen's personal business dealings.