DOVER, N.H. – After going as far as the U.S. Supreme Court, the legal battle over whether the Portsmouth Naval Shipyard is in New Hampshire or Maine is back in court, though one rung lower on the legal ladder.

Victor Bourre, a Dover activist trying to prove the shipyard belongs to New Hampshire, has filed a small-claims lawsuit in Dover District Court, arguing that Maine was wrong to tax his wages when he worked at the shipyard.

He says the state had no authority to withhold $816 in taxes from him in 1992. His suit names Philip Young of the Maine Revenue Service, who would not comment on the case.

Taxes are at the heart of the border dispute. Shipyard workers would not have to pay any taxes if the shipyard were in New Hampshire, which has no income tax.

The shipyard is on an island in the middle of the Piscataqua River, which separates the states.

New Hampshire took the issue to court, but the U.S. Supreme Court ruled in May 2001 that the shipyard is in Maine. New Hampshire asked the court to reconsider, but the justices refused.

Now Bourre, who worked at the shipyard for 24 years before retiring several years ago to dedicate more time to the legal battle, is hoping a lower court can do what the nation’s highest court wouldn’t.

“I’m ultimately going to win this thing, I guarantee you,” Bourre said.

In his latest lawsuit, Bourre asks for a refund from his 1992 Maine income taxes.

Asked if he believes a District Court judge will hear arguments on an issue that the U.S. Supreme Court already has dismissed, Bourre said the judge would have to because his evidence is solid.

“I can show all the congressional acts that the shipyard was established in New Hampshire,” Bourre said.

Meanwhile, Maine has begun the process of collecting roughly $500,000 in unpaid income taxes from New Hampshire residents employed at the shipyard.

Paul Stern of the Maine Attorney General’s Office said letters have been sent to shipyard employees regarding their status in terms of unpaid taxes. He said not all New Hampshire residents who owe taxes have been contacted yet.

“The vast majority of New Hampshire residents have duly paid their income tax to the state of Maine,” he said. “It would be wrong to reward the recalcitrant group by doing nothing.”