WikiLeaks founder Julian Assange hailed a UN panel's finding that he is under arbitrary detention as a "sweet victory" on Friday, urging Britain and Sweden to "implement the decision."
"This is a victory that cannot be denied," Assange said from a balcony of the Ecuadorian embassy in London, as he held up a copy of the panel's judgement.
He said the ruling was a victory of "historical importance" not just for him, his family and supporters, "but for the independence of the UN system."
"The UK lost, Sweden lost," he told dozens of journalists and supporters gathered below the balcony, urging the two nations to accept the UN's "binding covenants" on human rights.
"It is the end of the road for the legal arguments," Assange told reporters earlier via a video link from the embassy. "It is now the task of the states of Sweden and the United Kingdom to implement the decision."
Britain and Sweden have dismissed the ruling by the UN Working Group on Arbitrary Detention, a panel of independent legal scholars, that the Australian activist had been subject to arbitrary detention since his arrest in London in 2010 on Swedish allegations of rape and sexual harassment.
The group called on the two countries to allow the whistleblower to leave his refuge in the Ecuadorian embassy in London.
Ecuador Foreign Minister Ricardo Patino welcomed the UN panel's ruling and joined the calls for Assange to be allowed to go free.
Although the ruling is legally binding, the Geneva-based panel has no power to enforce it, and their decision was quickly dismissed by Britain and Sweden.
"This is, frankly, a ridiculous finding by the working group and we reject it," British Foreign Secretary Philip Hammond said.
Assange fears that an extradition to Sweden could be followed by an extradition to the United States, where he faces a possible life sentence for publishing secret government documents on his WikiLeaks platform. The US has yet to file any charges against him.
"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," said Seong-Phil Hong, who heads the UN panel.
Sweden rejected the opinion that Assange was being detained arbitrarily and argued that he runs no risk of extradition to the US because there has been no such request from Washington.
"Assange, voluntarily, has chosen to stay at the Ecuadorian embassy and Swedish authorities have no control over his decision to stay there," Anders Ronquist, the Foreign Ministry's head of legal affairs, wrote to the UN panel.
"He can come out any time he chooses," British chief diplomat Hammond said of Assange. "But he will have to face justice in Sweden if he chooses to do so."
Assange's lawyers said London and Stockholm should heed the UN opinion and let Assange go.
The UN decision "dispels the myth that Assange is a fugitive of justice or can walk out of the embassy," said Melinda Taylor, one of his lawyers.
Based on a Swedish arrest warrant on suspicion of sexual misconduct, the Australian whistleblower spent 10 days in isolation in a British prison and was then put under house arrest for 550 days.
Since 2012, he has been staying in the Ecuadorian embassy.
The UN panel judged Assange's situation as a form of arbitrary detention because of his initial solitary confinement, and because the lengthy detention was due to a lack of diligence by the Swedish prosecutor.
"Indefinite detention is actually a form of mental torture," Taylor said.
Speaking on the embassy balcony, Assange mentioned possible legal action against national governments under the UN Convention Against Torture (CAT).
"If unethical, illegal detention continues, there will be consequences," Assange said. "And that action can be taken in any state because the CAT has universal jurisdiction."
Sweden could have detained Assange based on preliminary investigations while he was still in the country, said Christophe Peschoux, the UN panel's secretary.
"But now, 5 years later, still no charges have been filed against him," he told reporters in Geneva.