One of the epic miscarriages of justice of our time is unravelling. The United Nations Working Group on Arbitrary Detention  - an international tribunal that adjudicates and decides whether governments comply with their human rights obligations -  has ruled that Julian Assange has been detained unlawfully by Britain and Sweden.

After five years of fighting to clear his name - having been smeared relentlessly yet charged with no crime - Assange is closer to justice and vindication, and perhaps freedom, than at any time since he was arrested and held in London under a European Extradition Warrant, itself now discredited by Parliament.

The U.N. Working Group bases its judgements on the European Convention on Human Rights and three other treaties that are binding on all its signatories. Both Britain and Sweden participated in the 16-month long U.N. investigation and submitted evidence and defended their position before the tribunal. It would fly contemptuously in the face of international law if they did not comply with the judgement and allow Assange to leave the refuge granted him by the Ecuadorean government in its London embassy.

Previous celebrated cases ruled upon by the Working Group include: Aung Sang Suu Kyi in Burma, imprisoned opposition leader Anwar Ibrahim in Malaysia, detained Washington Post journalist Jason Rezaian in Iran, for which both Britain and Sweden have given support to the tribunal. The difference now is that Assange's persecution and confinement endures in the heart of London.

The Assange case has never been primarily about allegations of sexual misconduct in Sweden - where the Stockholm Chief Prosecutor, Eva Finne, dismissed the case, saying, "I don't believe there is any reason to suspect that he has committed rape." Also, one of the women involved accused the police of fabricating evidence and "railroading" her, protested that she "did not want to accuse JA of anything." And a second prosecutor mysteriously re-opened the case after political intervention, then stalled it.

The Assange case is rooted across the Atlantic in Pentagon-dominated Washington, obsessed with pursuing and prosecuting whistleblowers, especially Assange for having exposed, in WikiLeaks, U.S. capital crimes in Afghanistan and Iraq: the wholesale killing of civilians and a contempt for sovereignty and international law. None of this truth-telling is illegal under the U.S. Constitution. As a presidential candidate in 2008, Barack Obama, a professor of constitutional law, lauded whistleblowers as "part of a healthy democracy [and they] must be protected from reprisal."

Obama, the betrayer, has since prosecuted more whistleblowers than all the US presidents combined. The courageous Chelsea Manning is serving 35 years in prison, having been tortured during her long pre-trial detention.

Telling us this truth alone earns Assange his freedom, whereas justice is his right.

The prospect of a similar fate has hung over Assange like a Damocles sword. According to documents released by Edward Snowden, Assange is on a "Manhunt target list." Vice President Joe Biden has called him a "cyber terrorist." In Alexandria, Virginia, a secret grand jury has attempted to concoct a crime for which Assange can be prosecuted in a court. Even though he is not an American, he is currently being fitted up with an espionage law dredged up from a century ago when it was used to silence conscientious objectors during World War I; the Espionage Act has provisions of both life imprisonment and the death penalty.

Assange's ability to defend himself in this Kafkaesque world has been handicapped by the U.S. declaring his case a state secret. A federal court has blocked the release of all information about what is known as the "national security" investigation of WikiLeaks.

The supporting act in this charade has been played by the second Swedish prosecutor, Marianne Ny. Until recently, Ny had refused to comply with a routine European procedure that required her to travel to London to question Assange and so advance the case that James Catlin, one of Assange's barristers, called "a laughing stock ... it's as if they make it up as they go along."

Indeed, even before Assange had left Sweden for London in 2010, Ny made no attempt to question him. In the years since, she has never properly explained, even to her own judicial authorities, why she has not completed the case she so enthusiastically re-ignited - just as she has never explained why she has refused to give Assange a guarantee that he will not be extradited on to the U.S. under a secret arrangement agreed between Stockholm and Washington. In 2010, the Independent in London revealed that the two governments had discussed Assange's potential extradition.

Then there is tiny, brave Ecuador.

One of the reasons Ecuador granted Julian Assange political asylum was that his own government, in Australia, had offered him none of the help to which he had a legal right and so abandoned him. Australia's collusion with the United States against its own citizen is evident in leaked documents; no more faithful vassals has America than the obeisant politicians of the Antipodes.

Four years ago, in Sydney, I spent several hours with the Liberal Member of the Federal Parliament, Malcolm Turnbull. We discussed the threats to Assange and their wider implications for freedom of speech and justice, and why Australia was obliged to stand by him. Turnbull is now the Prime Minister of Australia and, as I write, is attending an international conference on Syria hosted the Cameron government - about 15 minutes cab ride from the room that Assange has occupied for three and a half years in the small Ecuadorean embassy just along from Harrod's. The Syria connection is relevant if unreported; it was WikiLeaks that revealed that the United States had long planned to overthrow the Assad government in Syria. Today, as he meets and greets, Prime Minister Turnbull has an opportunity to contribute a modicum of purpose and truth to the conference by speaking up for his unjustly imprisoned compatriot, for whom he showed such concern when we met. All he need do is quote the judgement of the U.N. Working Group on Arbitrary Detention. Will he reclaim this shred of Australia's reputation in the decent world?

What is certain is that the decent world owes much to Julian Assange. He told us how indecent power behaves in secret, how it lies and manipulates and engages in great acts of violence, sustaining wars that kill and maim and turn millions into the refugees now in the news. Telling us this truth alone earns Assange his freedom, whereas justice is his right.