A Canadian retiree says he's been left with no choice other than to sell his house in Florida after being banned from the United States for what he believes was a long-buried bureaucratic snafu.

Mike Quinn, 70, of Niagara Falls, Ont., has spent the past two years trying to figure out why U.S. authorities dredged up a 15-year-old document as evidence he had once claimed to be a U.S. citizen.

"If I can't get this resolved in the next six months, I'm getting out of the States. Sell everything," Quinn said. "I'm not asking for forgiveness. I didn't do anything."

The professional engineer spent 16 years working in the United States, although he always considered Niagara Falls home. He left the U.S. in 2008 but frequently visited or shopped there using his long-held Nexus trusted traveller card to get across the border.

Quinn estimates he crossed the border more than 100 times — including to spend time at the house he bought in Port Lucie, Fla., in 2010 — without any major problems.

Things, however, changed in November 2014. American agents held him at the border for five hours. They claimed he had falsified his Nexus application by giving his marital status as single. Quinn denied the accusation, and told them he had never been married. The officers took his Nexus card.

He spent months trying to get it back — or at least to get an explanation from either the Americans or Canadians — to no avail.

The rule of law and due process mean little when governments want to get you. - Mike Quinn of Niagara Falls

"I never could figure out what the problem was, since I don't have a record," he said. "I'm a pretty boring person."

In April 2015, U.S. border agents again stopped him at the Peace Bridge. They accused him of having once claimed to have been a U.S. citizen. He denied having done so. Brushing off their warnings that he could be arrested or jailed for making a false declaration, he went on his way.

Several months later, he was again detained at the bridge.

"They took me in the back room and basically put me through the meat grinder," he said. "They pulled out this redacted registration form."

Records show the border officer produced a voter-registration form Quinn had signed in February 2000 — something he said he had completely forgotten about. After questioning him, the agent handed him a form to sign admitting to having made a false citizenship declaration with the intention of receiving a benefit: the right to vote.

The official refused his request to speak to a lawyer or judge and said he would be barred forever if he didn't sign, Quinn said.

"My head was pounding," Quinn said. "I had no idea what was going on."

He signed. The agent declared him inadmissible to the U.S. and sent him back to Canada.

An American lawyer wanted $30,000 to take the case

In retrospect, Quinn said, he recalled going into a Florida county office to renew his driver's licence in February 2000, but was told first to sign a voter-registration form that showed him as a U.S. citizen. He wonders whether the error might have been a bureaucratic slip when authorities issued him his Social Security Number.

Quinn said he advised the counter clerk of the mistake but she told him she could not renew his licence unless he signed the voter form and that she would have her supervisor fix the error. He signed — he said he realizes now that was a bad idea — and promptly forgot about it.

"I should never have been given the voter application form to sign, period, let alone been forced to sign it if I wanted to renew my Florida driver's licence," he said.

There's no indication he ever voted in the U.S., and he was removed from the Florida voting rolls in 2009 as inactive, according to the registrar.

Why the voter form surfaced 15 years later is a mystery. His best guess is that it may have been in retaliation for a complaint he made in the spring of 2014 against a sheriff in Florida. The officer had been drinking with a couple of women at a pond and firing his revolver around midnight, Quinn said.

In response to his complaints that he was badly treated and his pleas to have the ban reversed and his Nexus card reinstated, Homeland Security and Customs and Border Protection have told Quinn what he already knows — that he admitted to having falsely claimed U.S. citizenship, and, as a result, was declared inadmissible.

"Security procedures and legal concerns mandate that we can neither confirm nor deny any information about which may be within federal watch-lists or reveal any law-enforcement sensitive information," Homeland Security wrote him in February.

An American lawyer wanted $30,000 to take the case — money Quinn said he doesn't have given his two small pensions, one from Canada and one from the U.S. He also said he's unwilling to spend more than $1,000 to apply for a special inadmissibility waiver because it would entail an admission of wrongdoing. He's adamant he always lived by the book and never intentionally did anything illegal.

With nowhere else to turn, Quinn thinks he will have to give up his dream of living out his winter days in Florida.

"The rule of law and due process mean little when governments want to get you," he said.