"It's so ridiculous that people associate my name with Mitt Romney's tax returns, like I would have interest in it or know about it," Huntsman told The Salt Lake Tribune. "These fellows who wrote this book, they dwell on falsehoods and false rumors. They're nothing but supermarket, tabloid trash. They ought to be ashamed of themselves."
Huntsman added that he doesn't know anything about Romney's tax returns and never discussed the matter with Reid. Reid's office did not respond to a request for comment.
"If people have questions about Mitt Romney's taxes," Huntsman said, "they ought to ask him about it."
Huntsman was a national co-chairman of Romney's 2008 presidential bid and the two are third cousins, but the family relationship soured a bit in recent years when Huntsman's son, former Utah Gov. Jon Huntsman, jumped into the race with Romney.
Reid had charged on the Senate floor and in interviews last year that Romney didn't want to disclosure more than two years of tax documents because he hadn't paid any taxes for a long time. Reid, at the time, wouldn't say how he knew this, other than that it came from an investor in Romney's former firm Bain Capital.
Several commentators suggested at the time that Huntsman Sr. whose business partner Bob Gay previously served as managing director of Bain Capital was behind the claim.
"He didn't pay taxes for 10 years," Reid told Huffington Post during the 2012 campaign. "Now, do I know that that's true? Well, I'm not certain. But obviously he can't release those tax returns. How would it look? ... You guys have said his wealth is $250 million. Not a chance in the world. It's a lot more than that. I mean, you do pretty well if you don't pay taxes for 10 years when you're making millions and millions of dollars."
Huntsman Sr. flatly denied being the source last year and repeated it again Friday. He added that the Huntsmans and the Romneys aren't in any kind of spat.
"I have the highest respect for Mitt and [his wife] Ann and their family,' Huntsman Sr. said.
The new claim about Huntsman Sr. is in one of several tidbits from the presidential campaign summed up in "Double Down," according to The New York Times, which obtained an advance copy.
The book also charges that the younger Jon Huntsman, who served as U.S. ambassador to China under President Barack Obama, had repeatedly told the White House he wasn't going to make his own Oval Office run despite the fact he was already planning to do so.
Huntsman "repeatedly assured" the White House that he wasn't considering a presidential bid while simultaneously meeting with campaign strategists, the book says. While serving in the Obama administration, Huntsman's wife, Mary Kaye, was exchanging emails with the eventual strategist for their campaign, trying to be discreet by referring to the former Utah governor as "HE," The Times said, quoting from the book.
Huntsman's spokesman didn't respond to a request for comment.