A UN panel considering the case of Julian Assange has reportedly concluded that the WikiLeaks founder has been "arbitrarily detained".

Assange was granted political asylum in the Ecuadorian Embassy in London in 2012 to avoid extradition to Sweden. He is wanted there for questioning over allegations of sexual assault but he denies the claims.

In 2014 he filed a complaint against the UK and Sweden and said he was being “arbitrarily detained” in the Embassy as he could not leave without being arrested.

It is believed that the UN Working Group on Arbitrary Detention - which was considering Assange's request for relief - has ruled in his favour, according to the BBC.

The conclusion of the UN's report was confirmed by the Swedish Foreign Ministry. The decision is due to be published on Friday.

On Thursday, Assange said he would leave the Embassy if the panel ruled against him and accept arrest by UK police.

Wikileaks founder Julian Assange may surrender to police

“Should the UN announce tomorrow that I have lost my case against the United Kingdom and Sweden, I shall exit the Embassy at noon on Friday to accept arrest by British police as there is no meaningful prospect of further appeal," Assange said in a statement.

However, he added that he expected his passport to be returned and further attempts to arrest him to be blocked if “the state parties [were] found to have acted unlawfully”.

In December 2010, Assange was arrested on suspicion of sexual assault in Sweden and his extradition was ordered.

Failing to surrender for removal to Sweden in 2012 after seeking refuge in the Ecuadorian Embassy means he is subject to arrest by the Metropolitan Police.

The Met says it maintains this position.

In October 2015, the Met Police stood down the 24/7 police presence outside the Embassy and said “should [Assange] leave the Embassy the [Metropolitan Police Service] will make every effort to arrest him”.

A spokesman from the government said opinions from the UN Working Group on Arbitrary Detention would not be pre-empted.

"We have been consistently clear that Mr Assange has never been arbitrarily detained by the UK but is, in fact, voluntarily avoiding lawful arrest by choosing to remain in the Ecuadorean embassy.

In pictures: Julian Assange's 'arbitrary detention' Show all 14 1 /14 In pictures: Julian Assange's 'arbitrary detention' In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Wikileaks founder Julian Assange speaks from the Ecuadorian Embassy on December 20, 2012 in London, England. Getty Images In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Supporters of Julian Assange show banners as they wait for his appearance opposite the Ecuadorian Embassy yesterday (Frank Augstein/AP) In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' A supporter of WikiLeaks founder Julian Assange demonstrates outside Ecuador's embassy in central London on February 5, 2016 In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Assange speaking to the media outside the Ecuador embassy in 2012 In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Fashion designer and political activist Vivienne Westwood to visit Wikileaks founder Julian Assange In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Members of the media wait outside the Ecuadorian embassy where Wikileaks founder Julian Assange continues to seek asylum in February 2016. In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Supporters of Assange wait for the arriveal of Ecuadorian Foreign minister Ricardo Patino (Andrew Cowie/AFP/Getty Images) In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' A supporter outside the embassy, which is guarded by police. The 24-hour operation is said to have cost the British taxpayer £3 million (Tal Cohen/EPA) In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Supporters of the WikiLeaks founder Julian Assange at a protest outside the Ecuadorean embassy yesterday, where he has been holed up for three years In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Supporters have appeared at the embassy numerous times over the last year, especially when Mr Assange is set to appear, as he did yesterday (Frank Augstein/AP) In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' The Foreign & Commonwealth Office have made clear that: “The UK has a legal obligation to extradite Mr Assange to Sweden” (Chris Helgren/Reuters) In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' Demonstrators hold banners outside the Ecuadorean Embassy in London, where Wikileaks founder Julian Assange is staying In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention' In pictures: Julian Assange's 'arbitrary detention' In pictures: Assange's 'arbitrary detention'

"An allegation of rape is still outstanding and a European Arrest Warrant in place, so the UK continues to have a legal obligation to extradite Mr Assange to Sweden," he said.

The Australian fears Sweden will extradite him to authorities in the US where he could be put on trial over the activities of the WikiLeaks website, which has published thousands of classified military and diplomatic documents.

In 2010, WikiLeaks published a classified US military video which showed an attack by Apache helicopters that killed a dozen people in Baghdad three years earlier.

It was followed by the release of thousands of documents regarding the US-led military campaign in Afghanistan.