Media reports say the High Court in London ruled on December 10 that U.S. assurances were enough to guarantee Wikileaks founder Julian Assange would be treated humanely and directed a lower court judge to send the extradition request to Britain's interior minister for review.

“There is no reason why this court should not accept the assurances as meaning what they say,'' the High Court ruling stated, according to ABC News

Assange’s fiancé, Stella Moris, reportedly called the decision a “grave miscarriage of justice” and said Assange's lawyers would seek to appeal to the U.K. Supreme Court.

Assange, 50, is currently being held at London’s high-security Belmarsh Prison. The High Court ordered that he remain in custody pending the outcome of the extradition case.

In January, a lower court judge refused the U.S. request to extradite Assange to face spying charges over Wikileaks’ publication of secret military documents a decade ago.  The extradition was denied on health grounds.  

The United States appealed, challenging the notion that Assange’s mental health made him too vulnerable to withstand the U.S. judicial system. 

According to the BBC, the US had offered four assurances, including that Mr. Assange would not be subject to solitary confinement pre or post-trial or detained at the ADX Florence Supermax jail - a maximum security prison in Colorado - if extradited.

Lawyers for the US said he would be allowed to transfer to Australia to serve any prison sentence he may be given closer to home.

And they argued Mr. Assange's mental illness "does not even come close" to being severe enough to prevent him from being extradited.

But lawyers representing Mr. Assange argued the assurances over his future treatment were "meaningless" and "vague".

The United States has indicted Assange on 17 espionage charges and one charge of computer misuse over Wikileaks’ publication of thousands of leaked military and diplomatic documents.  The charges carry a maximum sentence of 175 years in prison, although Mr. James Lewis, a lawyer for the U.S. government, said “the longest sentence ever imposed for this offense is 63 months.”