WikiLeaks founder Julian Assange Julian Assange has started his latest legal action to try to block his extradition to Sweden at the Supreme Court in London.
Mr Assange, 40, was detained in Britain last year on a European arrest warrant, issued by a Swedish prosecutor, who wants to question him over accusations of sex crimes.
His lawyers argue that the warrant is invalid because it was issued by a prosecutor rather than a neutral judge or court.
The Supreme Court hearings will last two days.