The Empire has struck out.

Britain's Supreme Court on Wednesday defeated a bid by George Lucas' company to stop a prop designer making and selling replicas of the iconic stormtrooper helmets from the Star Wars films. The court did, however, prevent him from selling them in the United States.

Andrew Ainsworth sculpted the white helmets worn by the sinister galactic warriors in the original Star Wars film in 1977, and now sells replica costumes, made from the original molds, over the Internet. Lucasfilm Ltd. has been trying for years to stop him, in a battle that has climbed through the British courts.

Lucasfilm's lawyers argued that the stormtrooper suits are sculptures and therefore works of art covered by British copyright law. Two lower courts ruled in 2008 and 2009 that the costumes were props, not artworks, and so covered by a much shorter copyright period that has now expired.

The country's highest court on Wednesday upheld those decisions. The panel of five judges said "it was the Star Wars film that was the work of art that Mr. Lucas and his companies created. The helmet was utilitarian in the sense that it was an element in the process of production of the film."

But the judges agreed with Lucasfilm's lawyers —and a lower court — that Ainsworth had violated Lucas's copyright in the United States by selling costumes there.

Ainsworth's attorney, Seamus Andrew, said that means the designer may have to pay damages to Lucasfilm for the U.S. sales, but they are likely to be minor because he did not sell much merchandise there. The judges said Ainsworth had sold between $8,000 and $30,000 worth of goods in the U.S.

Andrew said that on the broader issue, "our client won, without a doubt."

He said the Supreme Court had been asked: "Could our client continue to manufacture and sell replica helmets and suits of armor without any form of license from George Lucas? And he can."

Ainsworth, 62, said he was delighted.

"I am proud to report that in the English legal system David can prevail against Goliath if his cause is right," he said. "If there is a Force, then it has been with me these past five years."

Lucasfilm said that "unfortunately" the court had upheld an "anomaly of British copyright law under which the creative and highly artistic works made for use in films -- which are protected by the copyright laws of virtually every other country in the world — may not be entitled to copyright protection in the U.K."