GENEVA (AFP) - Julian Assange's fiancee joined forces on Friday (June 4) with the mayor of Geneva and the UN's torture expert to seek the WikiLeaks founder's immediate release from a British jail and safe haven in another country.

In January, an English judge refused to allow Assange's extradition to the United States to face charges for leaking secret documents.

The 49-year-old remains in custody in a London jail awaiting a US appeal against the decision.

Assange's fiancee Stella Moris teamed up in Geneva with Nils Melzer, the UN special rapporteur on torture, and Geneva mayor Frederique Perler to call for his release and the scrapping of extradition proceedings.

They urged international organisations based in the Swiss city to help free Assange, and called on Switzerland and other democratic nations to offer the Australian former computer hacker a refuge from potential further prosecution moves.

"My hope is that it will end today, it's being going on for too long, it's an absolute aberration that Julian is in prison at all," Moris, who has two children with Assange, told AFP.

"He won his case of extradition at the lowest level in January and he is still in prison, and he is prosecuted for journalistic activities."

The lawyer said her fiance was struggling in the "grim environment" of Belmarsh prison, the top-security jail in south-east London.

"He is surrounded by dangerous criminals, his interactions are with criminals or with prison guards. He is isolated a lot of the time, his health is deteriorating and he hasn't seen his children since October."

Moris said she had not seen Assange since his Jan 6 court appearance.

Seven years inside embassy

Judge Vanessa Baraitser blocked his extradition to the United States for mental health reasons, but said that if released from custody pending the US appeal, there were substantial grounds to suspect that he might abscond.

If convicted in the United States, he faces a maximum sentence of 175 years in jail.

"Mr Assange still has an incentive to abscond from these as yet unresolved proceedings," said Baraitser.

Whilst on bail in 2012, Assange sought sanctuary in Ecuador's embassy in London, after Sweden issued an arrest warrant in connection with sexual assault allegations, which were later dropped.

He spent seven years inside the embassy until Quito revoked his citizenship in 2019. British police dragged him out and arrested him for jumping bail.

Assange is wanted in Washington to face 18 charges relating to the 2010 release by WikiLeaks of 500,000 secret files detailing aspects of military campaigns in Afghanistan and Iraq.

Melzer told reporters in Geneva that Assange's case was "probably one of the biggest judicial scandals in history".

"He's told the truth about misconduct of powerful states, of powerful corporations, he has challenged the powerful who do their business in the shadows," said the special rapporteur, who does not speak for the UN but reports his findings to the global body.