CNN said it had obtained the audio of the call between Giuliani, US diplomat Kurt Volker, and Andriy Yermak, a senior adviser to Ukrainian President Volodymyr Zelenskiy which it said was the precursor of a Trump-Zelenskiy call which was at the center of Trump's 2019 impeachment.
In the call, Giuliani said he wanted Zelenskiy to say he was putting a prosecutor in charge and "he's gonna investigate and dig up the evidence, that presently exists and is there any other evidence about involvement of the 2016 election, and then the Biden thing has to be run out," according to CNN.
Trump, a Republican, denounced as a political witch hunt allegations that he pressed Zelenskiy during a phone call to dig up dirt on Biden. The Democratic-led US House of Representatives voted to impeach Trump in December 2019, but he was acquitted by the then-Republican-dominated Senate early in 2020.
Trump lost the 2020 election to Biden, a Democrat, and left office in January 2021.
In April, federal prosecutors investigating Giuliani's business dealings in Ukraine at the time he was serving as Trump's lawyer raided his home and office, seizing cell phones and computers.
Giuliani, a former New York City mayor, has not been charged. He said after the raids that his conduct had been "absolutely legal and ethical."
Giuliani began representing Trump in April 2018 in connection with then-Special Counsel Robert Mueller's probe into Russian interference in the 2016 US presidential election.