Can an immigrant who resides legally in the U.S. on a work visa but who voted illegally in a presidential election year still become a naturalized U.S. citizen?

Yes, actually. Especially if the Department of Homeland Security sends a letter instructing him to request removal from the voter rolls.

That happened this summer in Putnam County, Tenn., where County Administrator of Elections Debbie Steidl says an immigrant who illegally registered to vote – and then voted – in 2004 is now seeking to become a U.S. citizen.

Steidl says the man gave her a form letter from the DHS instructing him to:

"Submit … evidence that you have been removed from the roll of registered voters. This can be accomplished by contacting your local election commission where you registered and voted. Submit a letter of explanation of why you registered to vote, and where you registered to vote, when you discovered that you were not a United States Citizen."

Steidl provided FoxNews.com with a copy of the letter, with the man's name and address redacted. Click here to see the letter.

She told FoxNews.com that, were the immigrant to be removed from the voter roll, as the DHS suggested, all traces of his illegal voting record would normally be shredded within two years.

"I went to my election commission and I said: ‘this frightens me for my country,'" she said. "They agreed with me. Why would you let someone who committed voter fraud become a citizen? That's what they're doing."

But immigration advocates say voting illegally can be an honest mistake, and the DHS is correct not to turn down immigrants who apply for citizenship solely because of it.

"I think a lot of people are truly very unaware about not being eligible to vote, and some election officials are maybe not clear enough on what's required," said Natalie Sullivan, director of the Immigration Advocates Network. "So immigration has a process in place to consider what the circumstances were, and decide on a case-by-case basis."

Sullivan said that, even if the records were shredded, the immigrant’s apparent admission to DHS could still provide evidence.

"If he has already admitted on the naturalization application that he previously voted, that is also a form of evidence… DHS is ultimately going to make the decision about what has allegedly occurred," she said.

The DHS did not respond to calls for comment. "Good moral character" is a requirement to obtain citizenship, and a memo issued by the Immigration and Naturalization Service in 2002 says immigration officers have discretion about whether to allow someone to become a citizen after admitting to voting illegally.

"Officers must balance the facts regarding the applicant’s unlawful voting or false representation as a U.S. citizen against other factors such as family ties and background," the memo reads.

A felony conviction of voter fraud from a court would bar someone from receiving citizenship, according to the memo. But in the Putnam County case, the time for prosecution is over.

"I went to the local DA, but the statute of limitations has run out," Steidl said. "He said, 'I can't do anything. You can write a letter, but it's just going to go in a file.' Maddening."

Putnam County District Attorney Randall York confirmed that the statute of limitations for vote fraud is two years. He declined to comment on the case.

Steidl said that as the administrator of elections, she is not allowed to question registrants about their citizenship when they apply. Everyone has to sign a form saying they are citizens. Asking for further evidence "would be considered discrimination,” she said.

Sullivan called Steidl's response to the letter an overreaction.

"She says the Department of Homeland Security is enabling this person -- I disagree," she said. "Their letter is meant to prevent any further acts of voting."

She said there were many benign reasons immigrants might vote, not knowing they are barred from doing so.

Indeed, many states now make it very easy to register to vote. Some will automatically register people applying for driver's licenses if they check off a box on their form and sign that they are a U.S. citizen.

Sullivan said immigrants who are not citizens may feel that voting is their civic duty and not realize that they are ineligible to vote.

"One reason might be enthusiasm for integrating, and for civic participation. A desire to see the laws change might be another… all that can be coupled with a lack of knowledge that the person is not qualified to do so."

But Steidl sees it differently.

"He signed a piece of paper that said he was a citizen of the U.S., just so he could vote. What else could he be willing to do?"