Rudy Giuliani’s lobbying work is said to be under scrutiny by the same U.S. attorney’s office he once led. The New York Times reported late Friday that federal prosecutors in Manhattan are looking into whether Donald Trump’s personal attorney violated lobbying laws as part of his Ukraine endeavors. While Giuliani has denied wrongdoing, Lev Parnas and Igor Fruman, two associates of his arrested earlier this week for alleged campaign finance violations, are believed to have worked closely with him in investigating the widely debunked corruption allegations against Joe Biden that Giuliani and Trump have sought to revive ahead of 2020.

Several law enforcement sources confirmed to The Daily Beast that Giuliani’s dealings are under scrutiny in connection with Parnas and Fruman’s arrest. “It's common sense,” one person with knowledge of the inquiry into Giuliani told The Daily Beast. “If people didn't look into this, they wouldn't be doing their jobs.” A second Justice Department source echoed that sentiment, along with a federal law enforcement official who said the matter is part of an ongoing investigation.

Giuliani’s work in Ukraine has previously raised questions about his lobbying status, with several Democratic senators appealing to the Department of Justice last year for information on his Foreign Agents Registration Act filings, a legal requirement for any U.S. citizen making contact with the government or media at the request of foreign politicians or officials.

Giuliani said last year he’d never filed a FARA registration, a claim which raised eyebrows in light of media reports that he’d performed lobbying work for clients in Ukraine. Ukrainian-Russian developer Pavel Fuks told The New York Times earlier this year that Giuliani had been employed as a “lobbyist for Kharkiv and Ukraine” in 2017, though Giuliani denied that claim.

—Harry Siegel, Pervaiz Shallwani and Noah Shachtman contributed reporting