US federal authorities raided the Manhattan apartment of former President Donald Trump's personal lawyer, Rudy Giuliani, on Wednesday amid a continuing investigation into the former New York mayor's dealings in Ukraine.

Iran Press/America: The move represents the highest-profile action yet as part of the inquiry into Giuliani's lobbying efforts in Ukraine at a time when he was searching for damaging information to assist Trump in the campaign against President Joe Biden.

The development was first reported by The New York Times.

Giuliani and his lawyer did not immediately respond to requests for comment.

But the former mayor's son, Andrew Giuliani, a former Trump aide, called the Justice action "extremely disturbing."

Speaking to reporters outside his father's apartment building late Wednesday, he said the investigation represented a "continued politicization of the Justice Department."

"This is disgusting ... absolutely absurd," he said.  

The US Justice Department declined to comment Wednesday; the FBI did not respond to inquiries. 

As the investigation played out in public in New York, federal investigators also served a search warrant early Wednesday at the home of Washington lawyer Victoria Toensing, who along with her husband, lawyer Joe diGenova, have been close to Giuliani.

US federal investigators have been examining Giuliani since at least early 2019 related to his business dealings with Ukrainian-born Lev Parnas and Igor Fruman, of Belarus, who had been indicted in the fall of 2019 on campaign finance charges.

An attorney, Kenneth McCallion, who has represented several Ukrainian clients in US court cases, including former Ukraine Prime Minister Yulia Tymoshenko, told USA TODAY at the time that agents asked him about Giuliani's business dealings with Parnas and Fruman.

The two men played instrumental roles in connecting Giuliani with Ukrainian officials as Giuliani sought information about the financial dealings thereof Biden's son, Hunter Biden.

Following Trump's unsuccessful re-election campaign, Giuliani led Trump's failed efforts to challenge Biden's election, as courts across the country rejected unfounded claims of voter fraud.

The raid represents the second time a personal lawyer for Trump has been targeted by federal authorities.

Three years ago, federal investigators raided the offices and home of Michael Cohen, as part of an investigation that led to his conviction.

Cohen pleaded guilty in 2018 to lying to Congress about plans to build a Trump Tower in Russia and, in a separate case, to pay off an adult film star and a former Playboy model who said they had sexual affairs with Trump before he was elected.

The attorney, who has since turned against Trump, insisted he acted at the direction of Trump, who has denied both affairs. Cohen had been sentenced to a three-year prison sentence but was released to home confinement because of the coronavirus pandemic.