The FBI is investigating a series of suspicious wire transfers to offshore companies linked to President Trump's former campaign manager Paul Manafort through which $3 million was moved around the world between 2012 and 2013, according to a report.

The transactions were resurfaced by the FBI as part of the agency's probe into whether Manafort committed tax fraud or helped to launder millions of dollars in revenue from corrupt deals for Ukrainian officials connected to Russian President Vladimir Putin, according to BuzzFeed News.

American financial institutions initially disclosed the transfers by five companies tied to Manafort — Global Endeavour Inc., Lucicle Consultants Ltd., and three others without current contact information -- to the Treasury Department as part of legally required "suspicious activity reports" that flag cash transactions of $10,000 or more in a single day.

The companies sent the funds in round-dollar amounts from countries known for laundering, such as Cyprus and St. Vincent and the Grenadine, law enforcement sources told BuzzFeed News.

Some of the money was received by home improvement contractors, a hedge fund, even a car dealership, all based in the U.S., the sources continued.

Manafort has become a target of investigations led by special counsel Robert Mueller, the FBI and Congress, but he and his representatives have vehemently denied any wrongdoing on his behalf.

The first indictments made under Mueller's Russia probe are expected to be revealed as early as Oct. 30.