Former New York mayor Rudy Giuliani's legal difficulties have escalated after the FBI seized phones and computers from his Manhattan apartment and office.
Mr Giuliani, who served as former president Donald Trump's lawyer, is the subject of criminal investigation into his dealings in Ukraine.
Investigators used a search warrant to enter his office and home in New York city where they seized the electronic devices.
Though Mr Giuliani has not been charged with any offences, it marks a significant development in the federal investigation into the lawyer’s activities in Ukraine, which were the focus of Mr Trump’s first impeachment trial.
In a statement issued through his lawyer, Mr Giuliani said the justice department was guilty of a “corrupt double standard”, claiming that it did not investigate “blatant crimes” by Democrats including Hillary Clinton. Instead, federal authorities were “running rough shod over the constitutional rights of anyone involved in, or legally defending, former President Donald J Trump”.
Mr Giuliani, whose son Andrew has said he intends to run for New York governor next year, became an internationally-known figure for his widely-praised leadership of New York city after the September 11th, 2001 terrorist attacks.
But in recent years he has recast himself as a defender of Mr Trump, serving as his personal lawyer during his presidency.
Before his stint as New York mayor, he was a prosecutor for the Southern District of New York – the same division that is now investigating his links to Ukraine.
It is believed that the federal government is examining whether Mr Giuliani illegally lobbied the Trump White House on behalf of Ukrainian officials. Two of Mr Giuliani's associates, Lev Parnas and Igor Fruman, were charged with campaign-finance crimes in 2019 and Mr Giuliani's work on the ground in Ukraine, where he sought to find incriminating information about then presidential candidate Joe Biden, is the subject of interest.
The FBI also executed a search of the Washington home of well-known lawyer and former justice department official Victoria Toensing, an ally of Mr Giuliani.
Mr Trump was impeached twice in office and his finances are the subject of various investigations.
In an interview on Thursday, Mr Trump described the treatment of Mr Giuliani as “very, very unfair”.
"Rudy loves this country so much, it is so terrible when you see things that are going on in our country with the corruption and the problems and then they go after Rudy Giuliani. "
Mr Biden said in an interview on Thursday that he was not told in advance about the raid on Mr Giuliani’s home and office. “I give you my word I was not. I made a pledge: I would not interfere in any way . . . or try to stop any investigation the justice department had under way. I learned about that last night when the rest of the world learned about it.”
Mr Biden’s son Hunter, whose presence on the board of a Ukrainian energy company while his father was vice-president has been criticised by Republicans, is also being investigated by the justice department in relation to taxes.