WASHINGTON, April 30 ― Donald Trump's former personal lawyer Rudy Giuliani denied yesterday he had ever represented a Ukrainian national, a day after federal agents searched his Manhattan apartment and office as part of a probe into his business dealings in Ukraine.

Giuliani said the agents seized seven or eight electronic devices and the search warrant included an allegation that he had failed to register as a foreign agent, a violation of lobbying laws.

"I've never represented a Ukrainian national or official before the United States government,” Giuliani said in an interview on Fox News.

Federal prosecutors have been investigating Giuliani for nearly 1-1/2 years over his Ukrainian business dealings while serving as Trump's attorney. He has not formally been accused of any wrongdoing.

Trump criticised the federal investigation into Giuliani yesterday.

"It’s very, very unfair,” Trump told Fox Business Network in a telephone interview. "Rudy is a patriot who loves this country and I don’t know what they’re looking for, what they’re doing. They said it had to do with filing of various papers.”

A spokesman for the Republican former president said in February that Giuliani was not representing Trump in any current legal matters.

Giuliani played a central role in Trump's failed effort to overturn his 2020 election defeat based on false claims of massive voter fraud.

Wednesday's search marked a significant step in the investigators' probe. A 2019 grand jury subpoena for Giuliani's financial records seen by Reuters showed that agents were examining possible money laundering, wire fraud, campaign finance violations, making false statements, obstruction of justice, and violations of the federal Foreign Agents Registration Act.

It marks the latest turn for Giuliani, the former mayor of New York who rose to national prominence following the Sept. 11, 2001, attacks and who once led the U.S. Attorney's Office in Manhattan that is now probing him.

Giuliani began representing Trump in 2018 amid a federal investigation into Russian interference in the 2016 presidential election, which Trump won.

Ahead of the 2020 election, Giuliani led an effort to dig up dirt on Democratic contender Joe Biden and his son Hunter in Ukraine. Biden defeated Trump and took office earlier this year. Both Biden and his son have denied wrongdoing.

The FBI warned Giuliani in late 2019 that he was the target of a Russian influence operation aimed at circulating falsehoods intended to damage Biden politically, the Washington Post reported, citing people familiar with the matter.

Giuliani lawyer Robert Costello did not immediately return a request for comment on the Post story.

Costello said on Wednesday that authorities had seized cellphones and computers and, along with Giuliani's son, Andrew, suggested that the investigation of his client was politically motivated - a charge the White House denied.

Biden said yesterday he had no notice of the Department of Justice's actions and was making good on his campaign pledge to maintain its independence.

"I made a pledge,” he told NBC News in an interview. "I would not interfere in any way. ... I learned about that last night when the rest of the world learned about it.”

Giuliani faces separate legal actions regarding his actions surrounding the November election and the deadly January 6 attack on the US Capitol by Trump supporters - one from a Democratic congressman and another from voting machine company Dominion Voting Systems. ― Reuters