Federal investigators in Manhattan executed search warrants early Wednesday at the home and office of Rudolph W. Giuliani, the former New York City mayor who became President Donald J. Trump’s personal lawyer, stepping up a criminal investigation into Mr. Giuliani’s dealings in Ukraine, three people with knowledge of the investigation said.
The investigators seized Mr. Giuliani’s electronic devices and searched his apartment on Madison Avenue and his office on Park Avenue at about 6 a.m., two of the people said.
Executing a search warrant is an extraordinary move for prosecutors to take against a lawyer, let alone a lawyer for a former president. It is a major turning point in the long-running investigation into Mr. Giuliani, who as mayor steered New York through the Sept. 11 attacks and earlier in his career led the same U.S. attorney’s office in Manhattan that is now investigating him.
Mr. Giuliani’s lawyer, Robert J. Costello, called the searches unnecessary because his client had offered to answer questions from prosecutors, except those regarding his privileged communications with the former president.
“What they did today was legal thuggery,” Mr. Costello said. “Why would you do this to anyone, let alone someone who was the associate attorney general, United States attorney, the mayor of New York City and the personal lawyer to the 45th president of the United States.”
The federal authorities have been largely focused on whether Mr. Giuliani illegally lobbied the Trump administration in 2019 on behalf of Ukrainian officials and oligarchs, who at the same time were helping Mr. Giuliani search for dirt on Mr. Trump’s political rivals, including President Biden, who was then a leading candidate for the Democratic presidential nomination.
The United States Attorney’s office in Manhattan and the F.B.I. had for months sought to secure a search warrant for Mr. Giuliani’s phones.
Under Mr. Trump, senior political appointees in the Justice Department repeatedly sought to block such a warrant, The New York Times reported, slowing the investigation as it was gaining momentum last year. After Merrick B. Garland was confirmed as President Biden’s attorney general, the Justice Department lifted its objection to the search.
While the warrants are not an explicit accusation of wrongdoing against Mr. Giuliani, it shows that the investigation has entered an aggressive new phase. To obtain a search warrant, investigators need to persuade a judge they have sufficient reason to believe that a crime was committed and that the search would turn up evidence of the crime.
Spokesmen for the F.B.I. and the U.S. attorney’s office declined to comment.
The investigation of Mr. Giuliani grew out of a case against two Soviet-born men who aided his mission in Ukraine to unearth damaging information about Mr. Biden and his son Hunter, who was on the board of a Ukrainian energy company. The prosecutors charged the two men, Lev Parnas and Igor Fruman, with unrelated crimes in late 2019 and a trial is scheduled for October.
While investigating Mr. Giuliani, prosecutors have examined, among other things, his potential business dealings in Ukraine and…