Senate Majority Leader Harry Reid, in calling out Republican candidate Mitt Romney for declining to release all but his most recent tax returns, suggested that Romney's late father, also a politician, would have been "embarrassed" at his son's stance.

The remark came as Reid quoted an unnamed former business acquaintance of Romney's as claiming the candidate had avoided taxes for a full decade -- that presumably being the reason he wouldn't want the returns to be made public.

"His poor father must be so embarrassed about his son," Reid said in an interview with the Huffington Post.

George Romney, a Michigan governor, released 12 years of tax returns during his unsuccessful bid for the Republican presidential nomination in 1968. His son has released only his 2010 tax return and an estimate for 2011, years when he was preparing for his own presidential bid or already running.

Reid said someone who had invested with Bain Capital, Mitt Romney's former venture capital firm, told the Democratic leader, "Harry, he didn't pay any taxes for 10 years."

Reid acknowledged that he had no evidence to back up such a claim. Yet he went on to suggest that Romney, though under no requirements to disclose more as presidential candidate, wouldn't get past the nominating process for a Cabinet position if he were to maintain the same level of financial privacy.

Romney has attempted to deflect criticisms of his decision not to release more tax returns, arguing that he has done everything the law requires.

His campaign repeated that refrain Tuesday in response to Reid's comments, with adviser Kevin Madden telling the Huffington Post that Romney had "gone above and beyond the disclosure requirements by releasing two years of personal tax returns in addition to the hundreds of pages of personal financial disclosure documents he has provided to the FEC and made public."

The campaign also has previously denied that Romney went any years without paying any taxes.