Billioniare financier George Soros contributed $6 million to the leading super PAC supporting Hillary Clinton's 2016 White House bid, according to the organization's latest filings. The donation brings Soros' tally of support to pro-Clinton groups in 2015 to $8 million.

Soros' December contribution topped all individual donations to Priorities USA Action, which raised $25 million in the second half of 2015, according to a report the group filed Sunday evening with the Federal Election Commission, Politico reported. The Soros donation brings the PAC's tally to $41 million for the 2015, giving it a sizable $36 million in the coffers going into 2016.

Several others made large contributions to Priorites USA Action in 2015, including media mogul Haim Saban and his wife Cheryl, who gave a total of $5 million, philanthropist Laure Woods, who gave $2.3 million, and investor Donald Sussman, who contributed $2.5 million, according to The Hill.

"We have raised significantly more resources than at this point in 2012, built a team of our Party's strongest leaders and activists, and are developing cutting edge strategies to reach Democratic and undecided voters in every battleground state," Guy Cecil, the group's co-chairman, wrote in a memo, according to The New York Times.

The Bernie Sanders campaign had a different message about fundraising on Friday - that it had brought in absolutely no money from super PACs. In a tweet, it howed the stark lack of super PAC fundraising they had done.

BREAKING: Sanders super PAC haul

$0.00

- Bernie Sanders (@BernieSanders) January 29, 2016

In a follow-up statement, the campaign elaborated on why that figure is important.

"Bernie doesn't want billionaires' money. He doesn't have a super PAC," campaign spokesman Michael Briggs said in the statement. "He believes you can't fix a rigged economy by taking part in the corrupt campaign finance system in which politicians take unlimited sums of money from Wall Street and other powerful special interests and then pretend it doesn't influence them."