Billionaire Sheldon Adelson has committed $25 million to an anti-Hillary Clinton super PAC, just one week before the presidential and congressional elections are decided on Nov. 8, according to a Fox News report late Monday.

Republican sources told the cable news station that Adelson may dump an additional $25 million on top of this donation into races for the White House, Senate and House of Representatives in the next few days as well.

Adelson had previously said he would give $100 million to help Republican nominee Donald Trump win the Oval Office, but has waited until the end to follow through on his promise.

The money was given to Future 45, a super PAC founded by the Ricketts family in Chicago, owners of TD Ameritrade. The Ricketts endorsed Wisconsin Gov. Scott Walker during the primary season and has only recently come around to endorsing and funding Trump's campaign. One source said Adelson was motivated over the weekend to help Trump after the FBI enhanced its investigation into Hillary Clinton's email activities.

Trump had announced the endorsement on Sunday, while speaking at Adelson's Venetian resort and casino in Las Vegas, but did not mention the financial component of the billionaire's backing.