Marco Rubio's PAC spent more than $40,000 trying to debunk the whispers that had long haunted the Florida Republican: that he had a 'zipper problem,' mistresses and a love child.

Researchers didn't find any compelling evidence of infidelity, but what Rubio allies did find was that the constant 'drip drip' of gossip came from a handful of South Florida Republicans who are now politically aligned with rival Jeb Bush.

Buzzfeed reporter McKay Coppins outlined the tenuous relationship between team Rubio and team Bush in an excerpt of his forthcoming book, 'The Wilderness,' explaining that Bush's people wanted Rubio sidelined before the 2016 race even began and tried using mistress gossip to do so.

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Marco Rubio's PAC spent more than $40,000 to zip up any talk about the senator having zipper problems and while they didn't find skeletons in the Florida senator's closet chatter throughout political circles continued

Jeb Bush (left) and his campaign deny spreading rumors about Marco Rubio (right) having a love child, but the gossip persists

'It's like whack-a-mole,' one California bundler who had been courted by Bush told Buzzfeed. 'They're going to try to take out everyone before the primaries even start.'

While Bush's official campaign has wholeheartedly denied stirring the Rubio rumor pot – 'Our campaign has never said anything of this nature and doesn't believe it,' Bush spokesman Tim Miller told Coppins. 'The candidates will be graded on their records both in the private sector and public office, as well as their plans for the future.'

Two prominent Bush allies were fingered by Buzzfeed as the voices behind the anti-Rubio whisper campaign.

The first was Ann Herberger, a Miami-based political fundraiser who switched teams from Rubio to Bush.

The second was a more prominent face in national political circles: CNN commentator Ana Navarro.

'They were circulating the rumors anew among donors and politicos and cautioning them to exercise due diligence before signing on with his campaign,' wrote Coppins.

Gossip girls? Jeb Bush supporters Ann Herberger (left) and Ana Navarro (right) were thought by Marco Rubio's allies to be two prominent voices circulating rumors about Rubio having sexual skeletons in his closet

Jeb Bush was there to congratulate Marco Rubio on winning a Senate seat in 2010 - though the two have become less friendly since then

Back in 2010, when Rubio won his U.S. Senate seat, Bush was at his side and even cried, as he introduced the young victor at Miami's Biltmore Hotel.

But since then the two Florida pols have gone their separate ways.

Starting in 2012, Rubio started laying the groundwork for a presidential run, whether it was the vice presidential slot on Mitt Romney's ticket or a full-on campaign in 2016.

Rubio tasked strategist Terry Sullivan to run his Reclaim America political action committee and Sullivan decided it was time to put those persistent zipper rumors to rest.

Sullivan hired the Sacramento-based firm named MB Public Affairs for the $40,000+ figure, to start trolling for skeletons in Rubio's closet

Rubio's aides, Coppins reported, warned the senator that the research would be 'about as invasive and unpleasant as a prostate exam,' but the Florida senator went through with it.

It's pretty typical for campaigns to do research on their own candidates, so they know what opposition research might be dug up.

Rubio insiders were pleased that the researchers found nothing tawdry in the senator's past.

But then as 2016 got underway, the rumors were sparked anew, particularly after Rubio wowed donors at a Koch brothers summit in Rancho Mirage.

'Jeb and his tight-knit 2016 team decided the young senator needed to be neutralized,' Coppins wrote. 'For their new mission, they adopted a code name: "Homeland Security.";

The 'Homeland Security' plan mostly meant getting Bush's donors and supporters in Florida to commit and endorse their candidate.

And the plan was successful as Rubio's team had trouble getting fundraising dollars from anyone in the state.

Outside of Florida, donors were balking too. The reason, potential supporters said, was the concern that opposition research on Rubio would eventually kill his candidacy. 'Talk coming out of Tallahassee' was often how it was worded, Buzzfeed said.

Eventually fingers pointed back toward Bush – specifically at Navarro and Herberger – but also at the candidate himself.

And while Bush's people denied having anything to do with stirring up the rumor mill, Rubio's people were skeptical too, seeing how Bush had supported Rubio so wholeheartedly during his 2010 Senate run.