A Swedish court has decided not to drop an arrest warrant against WikiLeaks founder Julian Assange.

The organisation asked the Swedish legal authorities to revoke the arrest warrant following a decision by a United Nations working group that he was being unlawfully detained.

Mr Assange has been living inside the Ecuadorian Embassy in London for more than three years, believing that if he travels to Sweden he will be taken to the United States for questioning over the activities of WikiLeaks.

A statement from Mr Assange's legal team said: "In defiance of the UN, Sweden's lowest court is keeping Assange detained.

"We are appealing and are confident Sweden's higher courts will enforce its international obligations and put an end to this terrible injustice, which has seen Mr Assange detained, without charge, for the last five and half years."

Mr Assange is wanted for questioning in Sweden over a sex allegation, which he denies.

WikiLeaks said it was a fact that there was an espionage case against him in the United States, pointing to the FBI telling a US court last week that it continued to actively pursue Mr Assange.

The organisation said the US Department of Justice filed a 113-page document to a court in March saying there is a pending national security prosecution against Mr Assange and WikiLeaks.

The UN panel called on the Swedish and British authorities to end Mr Assange's "deprivation of liberty", respect his physical integrity and freedom of movement, and afford him the right to compensation.

"The Working Group on Arbitrary Detention considers that the various forms of deprivation of liberty to which Julian Assange has been subjected constitute a form of arbitrary detention," the panel's head, Seong-Phil Hong, said when the findings were published earlier this year.

"The Working Group maintains that the arbitrary detention of Mr Assange should be brought to an end, that his physical integrity and freedom of movement be respected, and that he should be entitled to an enforceable right to compensation."

The Working Group said it considered that Mr Assange had been subjected to different forms of deprivation of liberty, including his initial detention in Wandsworth Prison in London, followed by house arrest and then confinement at the Ecuadorean Embassy.

WikiLeaks said it will appeal against today's decision by the Stockholm District Court.