One day after Senator Marco Rubio (R-FL) denied his presidential campaign was involved in the production of the so-called Russia dossier against President Donald Trump, the former Trump presidential primary rival candidate’s top campaign donor, Paul Singer, was revealed to have originally funded the firm’s anti-Trump research through the Washington Free Beacon.

Singer, a GOP mega-donor and open borders enthusiast, was behind–through the Free Beacon–the original efforts that Fusion GPS was engaged in to produce opposition research on Trump during the 2016 presidential election. After the primary was over and Trump was the GOP nominee in 2016, the effort shifted from a Free Beacon-and-Singer-backed Fusion GPS mission to a mission funded by failed Democratic presidential nominee Hillary Rodham Clinton’s campaign.

But, when pressed on the question this week, Rubio sought to distance himself and his campaign from his main donor’s efforts.

“As far as whether it was my campaign, it wasn’t and I’ll tell you why,” Rubio told CNN. He went on:

I was running for president. I was trying to win. If I had anything against Donald Trump that was relevant and credible and politically damaging, I would’ve used it. I didn’t have it. I don’t know who it was. The one thing we do know, this thing about the dossier you’re discussing, all those press accounts, and I’m just going off press accounts, they all make it abundantly clear that the work that Mr. Steele did on that dossier didn’t even start until April or May or June, after the Republican primary was over. So that was the DNC, and that was the Clinton campaign.

But the Washington Examiner reported late Friday that lawyers for the Singer funded-Washington Free Beacon paid for the project from fall 2015 to spring 2016. Only after that did Hillary Clinton’s campaign and the Democratic National Committee pick up the tab for the research efforts, which would later lead to the production of the so-called Russia dossier, the Washington Post reported Tuesday.

Singer, a Wall Street hedge-fund billionaire, bankrolled “Gang of Eight” amnesty leader Rubio’s 2016 presidential bid. Both share a mutual belief in amnesty for illegal aliens and have called for increases in immigration.

As then-Breitbart News correspondent and now Trump White House aide Julia Hahn reported in 2015: “Singer’s decision to throw his financial weight behind the donor-class 2016 favorite, Marco Rubio, has sparked fresh questions about Rubio’s coziness with the financial interests funding his career.” Hahn wrote:

Singer was a major financial force behind the Rubio-Obama amnesty and immigration expansion push in 2013. As Politico reported at the time, Singer “quietly go[t] involved in the fight for immigration reform, making a six-figure donation… to the National Immigration Forum”— a George Soros-backed organization that lobbied for Rubio’s legislation to issue 33 million green cards to foreign nationals in the span of a single decade. The announcement of Singer’s endorsement highlights an intra-party tension that has emerged with new strength since Paul Ryan’s inauguration as Speaker of the House.

Following Singer’s announcement, then-presidential nominee Donald Trump tweeted, “I see Marco Rubio just landed another billionaire to give big money to his Superpac, which are total scams. Marco must address him as ‘SIR’!”

I see Marco Rubio just landed another billionaire to give big money to his Superpac, which are total scams. Marco must address him as "SIR"! — Donald J. Trump (@realDonaldTrump) October 31, 2015

Trump tweeted again, the following day, calling Singer “Mr. Amnesty.”

Further proof that Gang of Eight member Marco Rubio is weak on illegal immigration is Paul Singer's, Mr. Amnesty, endorsement.Rubs can't win — Donald J. Trump (@realDonaldTrump) November 1, 2015

In addition to backing Rubio, open borders, and opposition research on Donald Trump, Singer is also a funder of efforts to legalize same-sex marriage and has dumped hundreds of thousands of dollars into supporting Common Core governmental control of education.

Breitbart News reached out to Rubio’s office for comment on Friday evening to see whether the senator regrets accepting financial backing from Singer, whether the senator thinks what Singer did was acceptable, and to see whether he thinks Singer should testify before Congress about his involvement.

Rubio’s office did not answer any of those questions from Breitbart News, but he did send the following statement from a spokeswoman: “Other than the Clinton campaign, Senator Rubio and his team do not know who contracted Fusion GPS and had never even heard of them or their alleged research until it was posted online earlier this year.”

Amanda House is Breitbart News’ Deputy Political Editor. You can follow her on Twitter at @AmandaLeeHouse.