Giuliani under investigation for alleged campaign finance, lobbying breaches: report

President TrumpDonald John TrumpBiden says his faith is 'bedrock foundation of my life' after Trump claim Coronavirus talks on life support as parties dig in, pass blame Ohio governor tests negative in second coronavirus test MORE’s personal attorney Rudy GiulianiRudy GiulianiGiuliani says Black Lives Matter is 'domestic terrorist' group Commission on Presidential Debates rejects Trump campaign call for earlier debate The Hill's Campaign Report: COVID-19 puts conventions in flux  MORE is under investigation by federal prosecutors over possible campaign finance violations and accusations he failed to register as a foreign agent, Bloomberg reports.

Multiple U.S. officials told the outlet that the probe into Giuliani’s financial dealings could also lead to charges of violating bribery or conspiracy laws, with one adding that his work alongside the president has raised counterintelligence concerns.

The former New York City mayor is at the heart of House Democrats’ impeachment inquiry into Trump, as investigators look into Giuliani's role in efforts to pressure Ukrainian President Volodymyr Zelensky to investigate one of the president's chief political rivals, former Vice President Joe BidenJoe BidenBiden says his faith is 'bedrock foundation of my life' after Trump claim Biden clarifies comments comparing African American and Latino communities Kanye West may have missed deadline to get on Wisconsin ballot by minutes: report MORE

Giuliani, if indicted, would likely affect Trump's defense strategy amid the ongoing probe.

“I would not be surprised if he gets indicted,” Mimi Rocah, a former federal prosecutor with the U.S. Attorney’s Office for the Southern District of New York, told Bloomberg. “It’s clear Giuliani is up to his ears in shady stuff and there’s tons of smoke.”

Federal prosecutors in Manhattan are also investigating whether Giuliani broke lobbying laws in dealing with Ukraine, as well as his efforts to undercut Marie Yovanovitch, the U.S. ambassador to Ukraine who was ultimately recalled in the spring as Trump sought to pressure the country to probe Biden.

Two of Giuliani’s associates, Lev Parnas and Igor Fruman, have been charged with campaign finance violations in funneling hundreds of thousands of dollars into a pro-Trump political action committee.

Parnas’s attorney has said his client warned Ukrainian officials that the Trump administration would freeze military aid to Ukraine unless Kyiv announced an investigation into Biden.

In an op-ed published Tuesday, one day before the House held its first public hearings in the impeachment inquiry, Giuliani slammed the “unprecedented, constitutionally questionable” probe. He has maintained the July 25 call between Trump and Ukraine that lies at the heart of the inquiry was “innocent.”

Updated at 8:25 p.m.