“I don’t know who Harry was talking to,” Axelrod told Chris Wallace on “Fox News Sunday.” “The point here, though, Chris, is the Romney campaign and Gov. Romney can resolve this in 10 seconds – they can release the tax returns.”

He noted that the presumptive Republican presidential nominee gave 23 years of returns to John McCain and has only released one year to the American people.

“Why don’t they just put this to rest?” he said. “What is it that he’s hiding?”