It's Jon Huntsman Sr, right Harry?

Harry Reid's source. Probably. Harry Reid has a Republican source who has told him that Mitt Romney didn't pay taxes in 10 years. Who could he possibly known that would have that information? Former Utah Gov. Jon Huntsman's dad sounds like the likely source.

Jon Huntsman Sr, is business partners with Robert C. Gay, who also happened to be Bain's managing director between 1989 and 2004. And if anyone knows the machinations Bain used to evade taxes for itself and its partners, well, it would be the guy in charge of the firm's finances.

Huntsman is also a Republican and a Mormon (like Harry Reid). As governor of next-door Utah, his son (who also served in the Obama administration as ambassador to China) likely developed a close working relationship on regional issues.

Want more? The Huntsman family gave some serious scratch to Reid's reelection campaign:

Indeed, the Huntsmans have long been Reid supporters, although the former governor, who is scheduled to be be in Nevada on Friday, has never given directly to Reid's Senate campaigns.

[Jon Huntsman, Jr's] parents and a couple of his brothers (Peter, James) and some in-laws have. And his Dad even helped the Nevada Democratic Party ($5,000) in 2008. I'm told Reid has known the senior Huntsman since the 1990s and is friendly with the son, too.

Here's a list of the donations from the GOP candidate's family to Reid (with help from CQ MoneyLine):

Jon Huntsman, Sr., Karen Huntsman $9,600 (2/4/09)

Peter, Brynn Huntsman  $9,600 (12/31/09)

James, Marianne Huntsman     $4,600 (11/30/09)

Jon Huntsman, Sr.  $2,000 (11/2/04)

Sure, the evidence is circumstantial, but still pretty solid, wouldn't you say?

5:13 PM PT: Reid said his source was a Bain investor. Not sure if Huntsman Sr fits the bill just yet, but Bain has certainly invested in Huntsman:

Huntsman Corp. Friday announced a deal in which venture capital firm Bain Capital Inc. will invest more than $600 million in Huntsman.

5:33 PM PT: Great point, from the comments:

Remember it was a Huntsman daughter who penned

an article at HuffPo with Ryan Grim that had sources saying Romney would have never ran if he knew he had to open up his tax filings.  

Does the Huntsman family talk Romney's taxes around the dinner table?

by Jacoby Jonze

5:42 PM PT: The blogger Cannonfire came to this conclusion last Sunday, and his reasoning is far more developed than mine.

Now he thinks it's Jr, but his reasoning makes me even more convinced it was one of the Huntsmans. My money is still on Sr.

7:35 PM PT: Oooh, I had forgotten that Huntsman is skipping the GOP convention, certainly pointing to a major rift with his party and nominee.