LONDON: Britain's Supreme Court ruled on Wednesday WikiLeaks founder Julian Assange can be extradited to Sweden over alleged sex crimes, but gave him two weeks to seek to reopen the case.

Judges at Britain's highest court rejected by a majority of 5-2 Assange's argument that a European arrest warrant for his extradition was invalid.

Two lower courts have already ruled in favour of the extradition of Assange, a self-styled anti-secrecy campaigner and bane of Washington.

Swedish prosecutors want to question Assange over allegations of rape and sexual assault made by two female former WikiLeaks volunteers, and he has been fighting a lengthy legal battle against extradition since his arrest in Britain in Dec 2010.

The former computer hacker gained international prominence in 2010 when WikiLeaks began releasing secret video footage and thousands of US diplomatic cables about Iraq and Afghanistan, in the largest leak of classified documents in US history.

That made him a hero to anti-censorship campaigners but he was regarded as a menace by Washington and other governments.

Assange also faced widespread criticism that he had put lives at risk by blowing the cover of sources who spoke to diplomats and intelligence agents in countries where it was dangerous to do so.

Since then, WikiLeaks has faded from the headlines due to a dearth of scoops and a blockade by credit card companies that has made donations to the site almost impossible.

Assange's personal standing has been damaged by the Swedish sex case and he has lost support from most of his celebrity backers.

Since his detention, he has mostly been living under strict bail conditions at the country mansion of a wealthy supporter in eastern England. His associates say that amounts to 540 days under house arrest without charge.

Assange's appeal hinges on a legal technicality rather than the substance of the allegations of sexual misconduct or his claims that the United States has been putting pressure on Britain and Sweden to take action against him.

His lawyers argued the European Arrest Warrant (EAW) was invalid because it was issued by a prosecutor and not a judge or a court as required in Britain. Prosecutors acting for Sweden say different countries have different legal procedures which are allowable under the agreed EAW format.