President Donald Trump defended his personal attorney Rudy Giuliani on Saturday amid reports that federal prosecutors are investigating whether the former New York City mayor broke lobbying laws in his efforts to oust the former U.S. ambassador to Ukraine Marie Yavonovitch.

"So now they are after the legendary 'crime buster' and greatest Mayor in the history of NYC, Rudy Giuliani," Trump tweeted. "He may seem a little rough around the edges sometimes, but he is also a great guy and wonderful lawyer."

In defending Giuliani, Trump revived one of his recurring conspiracy theories that a "Deep State" of entrenched bureaucrats and law enforcement officers are continuing to undermine him and his associates. "Such a one sided Witch Hunt going on in USA. Deep State. Shameful!" he said.

His vocal defense of the embattled attorney comes just a day after he seemed to put distance between himself and the former mayor when asked if Giuliani still worked for him. "I don't know. I haven't spoken to Rudy. ... He has been my attorney," the president said.

Following those remarks, Giuliani told The Washington Post that he was still Trump's lawyer.

The president's tweet follows a report in The New York Times that federal prosecutors in Manhattan are investigating Giuliani's efforts to have Yavonovitch recalled in a broader effort to pressure Ukraine into investigating former Vice President Joe Biden's son, who sat on the board of a Ukrainian energy company.

Two of Giuliani's associates, Lev Parnas and Igor Fruman, were arrested Wednesday on charges of campaign finance violations. According to an indictment that federal prosecutors unsealed Thursday, the men were working for Ukrainian officials to remove Yovanovitch from her job.

Giuliani has admitted to trying to oust Yovanovitch but denies violating foreign lobbying disclosure laws because he was acting on behalf of the president, not a former Ukrainian prosector whom he has worked with who opposed Yovanovitch, he told the Times.