An FBI whistleblower named Johnathan Buma has alleged that Rudy Giuliani may have been compromised by Russian intelligence during his work for Trump's 2020 campaign. Buma claims the FBI investigated Giuliani's relationship with a Ukrainian oligarch Pavel Fuks, who was assessed to be an asset of Russian intelligence. Giuliani reportedly received $300,000 from Fuks for legal work. Buma's investigation found that Giuliani consorted with several Ukrainians who were later sanctioned by the U.S. as spreading Russian disinformation, including Andriy Derkach. However, some within the FBI allegedly blocked further investigation. Giuliani also attempted to produce an anti-Biden propaganda film with sources connected to Russian disinformation campaigns, though it was ultimately unsuccessful.