After one candidate served prison time for tax fraud, of course taxes would be an issue in this race for Congress. 

"I think the public has a right to know what's in his taxes," said Rep. Dan Donovan of Staten Island. "He was convicted of tax fraud. I suspect the IRS is probably auditing him every year since that conviction."

"Donovan hasn't accomplished anything since he has been congressman. Why would I listen to anything that he says?" former Rep. Michael Grimm said.

It's only Donovan releasing his 2017 tax returns to NY1. They show he had more than $360,000 in income last year. More than half of that was Donovan taking $200,000 out of a deferred compensation plan to buy a house. He gave a little more than $5,000 to charity. 

Grimm has filed an extension, and even then, he is brushing off the whole tax issue as a stunt.

"I've never been asked to release my taxes," he said. "It's not required by the FEC, so it's just a stunt by Donovan. He is releasing his taxes like he is doing something."

"He is hiding behind the fact that he doesn't want to release his taxes because he is hiding something, just like he hid things from our community during the 2014 election," Donovan said. "The public should demand from this man for him to release his taxes."

Donovan's campaign has claimed Grimm owes hundreds of thousands dollars in back taxes to New York State.  

According to the state Department of Taxation and Finance, Grimm has a more than $479,000 tax warrant for back sales tax, interest and penalties associated with the business he used to run. 

Tax issues with that business is what sent Grimm to prison. He is disputing that state bill. 

"Those penalties are completely inappropriate," he said. "I have a very good tax attorney who says he has never seen this before. It's pending. We are fighting it tooth and nail and I believe we are going to win."

This tax issue is the latest dispute in what has become a nasty race. The primary election is still two months away.