The Supreme Court ruled on Wednesday that WikiLeaks founder Julian Assange can be extradited to Sweden over alleged sex crimes, closing his final legal avenue of appeal in Britain.

"The request for Mr Assange's extradition has been lawfully made and his appeal against extradition is accordingly is dismissed," said Supreme Court president Nicholas Phillips.

The internet whistleblower, who enraged Washington by releasing a flood of state and military secrets on his website, has been fighting deportation since his arrest in London in December 2010 on aEuropean arrest warrant.

Britain's top court was his final avenue of appeal under UK law, after two lower courts ruled he should be sent to Sweden for questioning over allegations of rape and sexual assault made by two WikiLeaksvolunteers.

But Assange, who will has been living under tight restrictions on his movement for 540 days, now has the option of a last-ditch appeal to the European Court of Human Rights. AFP