President Donald Trump's embattled personal attorney, Michael Cohen, is expected to part ways with his current lawyers and hire new counsel as federal investigators continue to dig into his business dealings, a source close to Cohen told NBC News.

Cohen's split from Stephen Ryan and co-counsel Todd Harrison could signal a change in legal strategy but does not necessarily indicate that Cohen has decided to cut a deal with federal prosecutors.

Cohen has not even spoken with prosecutors involved in the inquiry, according to people familiar with the matter. Before a plea agreement, Cohen and his attorneys would need to meet with prosecutors in an organized meeting to discuss what he could offer — sometimes called a "queen for a day" session.

Cohen, often described as Trump's "fixer," is the subject of a probe by the U.S. attorney in Manhattan focusing on business matters, including a $130,000 payment to adult film actress Stormy Daniels just before the 2016 election.

Daniels, whose real name is Stephanie Clifford, says she had sex with Trump more than a decade ago and is suing both Trump and Cohen to invalidate the nondisclosure agreement she signed. Trump denies having an affair with Clifford.

Meanwhile, special counsel Robert Mueller, who is investigating Russian interference in the 2016 election, turned up information that he referred to the U.S. attorney's office in Manhattan.

In April, the FBI raided Cohen's law office and hotel room, seizing boxes of documents, phones, electronic devices, and computer equipment.

At a recent court hearing, prosecutors said they were still sorting through the material and needed more time to piece together the contents of a shredder and gain access to a BlackBerry.

Even before the raids, federal investigators had been monitoring Cohen's phone lines, multiple senior officials and individuals with knowledge of the legal proceedings have told NBC News.

The calls were logged by what is commonly referred to as a pen register, which records the number of the phone that made the call and the number that received it, but does not record the contents of any conversation.

Cohen has denied wrongdoing.

A longtime Cohen business partner agreed in May to cooperate with the government as part of a plea deal, according to a person with direct knowledge of the proceedings.

Evgeny Freidman, 47, a disbarred lawyer who is known as the "Taxi King," pleaded guilty to a low-level felony in Albany County Court, in upstate New York, for stealing nearly $5 million in state taxes and agreed to cooperate in state or federal investigations.

For years, Freidman, a Russian immigrant, has managed Cohen's taxi medallions, which give owners the right to operate New York City yellow cabs. Multiple people familiar with the proceedings would not say if Freidman's cooperation was specific to the ongoing federal criminal investigation into Cohen.

Trump has said he doesn't think Cohen will turn on him.

In a series of tweets in late April, Trump claimed some reporters are "going out of their way to destroy Michael Cohen and his relationship with me in the hope that he will 'flip.' "

"Michael is a businessman for his own account/lawyer who I have always liked & respected," he tweeted. "Most people will flip if the Government lets them out of trouble, even if it means lying or making up stories. Sorry, I don’t see Michael doing that despite the horrible Witch Hunt and the dishonest media!"

On Wednesday night, Rudy Giuliani, another Trump lawyer, told NBC News, “I have no information suggesting Cohen is going to flip and there’s nothing involving the president even if he did and therefore I’m not concerned.”

Giuliani also said he spoke with Trump about his broader legal strategy as it relates to Mueller while Trump was on Air Force 1 heading back from Singapore. “It was just going over the options that exist and leaving the rest for in-person conversations, which we’ll have over the next few days,” Giuliani said.

Giuliani said the president still wants to do an interview with Mueller but added, “The concerns are all ours, as his counsel.”

No formal notice of the change in Cohen's attorneys has been filed with the court.