U.S. Republican presidential candidate Donald Trump speaks at a campaign event at the Indiana Theater in Terre Haute, Indiana, May 1, 2016. Reuters/Aaron P. Bernstein

The head of Donald Trump’s presidential campaign said Sunday he has no reason to believe the real estate mogul and presumptive Republican nominee is hiding a bombshell in his tax returns.

Trump said Friday on ABC’s “Good Morning America” that voters have no right to see his tax returns before they vote, even though presidential candidates for the last 40 years have released their returns on a routine basis.

Paul Manafort, Trump’s chief strategist, said on CNN’s “State of the Union” it is his understanding that the returns are “not complete yet,” and that the media is interested, but the public isn't. Manafort said Trump’s returns for the last eight years are being scrutinized by the IRS, and Trump has said he will not release the returns until that audit is complete.

Asked why Trump doesn’t release any returns from before the audit period, Manafort said releasing anything filed more than eight years ago would be irrelevant. Presumptive Democratic presidential nominee Hillary Clinton has posted eight years of tax returns on her website.

Paul Manafort, advisor to Republican presidential candidate Donald Trump's campaign, checks the teleprompters before Trump's speech at the Mayflower Hotel in Washington, April 27, 2016. Chip Somodevilla/Getty Images

Ohio Sen. Sherrod Brown, an early Clinton supporter, denied the former secretary of state is the wrong person to question Trump keeping his tax returns under wraps, given her refusal to release the text of paid speeches she gave at Goldman Sachs.

Some have speculated the returns would show Trump isn’t as rich as he says he is or indicate he’s stingy when it comes to charitable giving.

“Tax returns would indicate a lot if he would release them,” Brown said on “State of the Union.”

The New York Times published a story Saturday highlighting Trump’s treatment of women over the years, and the Washington Post last week reported Trump acted as his own publicist and used a fake name in an interview with People magazine in the 1990s in which he bragged about his exploits with women.

“These are things he’s going to answer for, but these are from many years ago. As Christians judging each other, I think is problematic. I think when people live in glass houses and throw stones is when people get in trouble,” Republican Party Chair Reince Priebus told ABC’s “This Week” Sunday.

“People just don’t care. People look at Donald Trump and Hillary Clinton and say, ‘Who’s going to bring an earthquake to Washington?’ … Tradition playbook and analysis don’t apply. … I don’t know the truth of these things. … After a year of different stories, nothing applies,” Priebus said on “Fox News Sunday.”

Manafort said he’s not convinced the voice on the tape published by the Washington Post is Trump. He said that just because the person claiming to be John Miller uses the same cadence and phraseology as Trump doesn’t mean anything.

“I could barely understand it. If he [Trump] says [it's] not him, I believe him,” Manafort said, adding he uses the same words as Trump after working with him for several months.