LONDON â€"  WikiLeaks founder Julian Assange on Wednesday lost his legal fight at Britain's Supreme Court against extradition to Sweden.

The London court announced its judgement in a hearing at around 9:15am local time.

The 40-year-old Australian is wanted in Sweden to face questioning over alleged sex crimes against two women.

He has now exhausted all his legal options in Britain, but could still make a last-ditch appeal to the European Court of Human Rights.

Assange lodged his appeal against extradition with the Supreme Court in February, with his lawyers arguing the European arrest warrant used to seek his extradition was not valid as the Swedish prosecutor did not have sufficient authority to order the extradition.

This was rejected by a majority of five to two by the Supreme Court justices.

Attorneys for Assange secured a two-week stay however, arguing the decision by the judges was based on a point of law that was not discussed in court. Dinah Rose QC said the majority of members of the Supreme Court panel had made their decision based on the Vienna Convention on the Law of Treaties -- which was never brought up at the time. She may decide to challenge the validity of Wednesday's ruling on that basis.

Assange will not be extradited until that two-week period is completed.

Once in Sweden, he would then be tried behind closed doors as rape trials in the country are held in "secret."

Assange fears that if he is sent to Sweden he will then be extradited to the US for prosecution over charges associated with his WikiLeaks website, which released hundreds of thousands of classified diplomatic cables that revealed a mass of US secrets.