The FBI on Monday raided the New York City office and residence of President Donald Trump's personal attorney Michael Cohen, seeking evidence related to the payment Cohen made to porn star Stormy Daniels on the eve of the 2016 presidential election.

The Washington Post, citing a source familiar with the case, reported that Cohen is being investigated for crimes possibly related to bank fraud and campaign finance violations.

The raids came after federal prosecutors in New York City obtained a search warrant following a referral from special counsel Robert Mueller, Cohen's lawyer said.

At a White House event Monday evening, Trump slammed the raid on Cohen's office as a "disgraceful situation."

"It's a total witch hunt," Trump added before tearing into the entire special counsel investigation, his own attorney general and what he described as a lack of focus on former presidential opponent Hillary Clinton.

Mueller is investigating Russian interference in the 2016 presidential election and related issues, including possible collusion by officials in the Trump campaign with Russians.

NBC News reported that one raid occurred at a law office at 30 Rockefeller Plaza, located in midtown Manhattan. FBI agents also raided a room at the Loews Regency Hotel in Manhattan, where Cohen has been staying, and executed the warrants there.

A doorman at the Regency said, "They are still here," when asked about the FBI.

A woman who answered a call placed to Cohen's room in the hotel said she was his wife. When asked if the FBI was in the room, she hung up.

Sources told NBC News that the raid was set in motion after Mueller's team became aware of certain information but concluded it did not fall under their mandate and passed the issue on to federal prosecutors in New York.

Sources said the search was related to $130,000 in payments that Cohen has said he made to Daniels just before the presidential election.

Daniels has said that money was given to her in exchange for her agreement to keep quiet about an affair she had with Trump that began in 2006. The White House has denied that Trump had sex with Daniels.