This article is more than 1 year old

This article is more than 1 year old

Julian Assange, the fugitive WikiLeaks founder whose diplomatic sanctuary in the Ecuadorian embassy appears increasingly precarious, is launching a legal challenge against the Trump administration.

Lawyers for the Australian activist have filed an urgent application to the Washington-based Inter-American Commission of Human Rights (IACHR) aimed at forcing the hand of US prosecutors, requiring them to “unseal” any secret charges against him.

The legal move is an attempt to prevent Assange’s extradition to the US at a time that a new Ecuadorian government has been making his stay in the central London apartment increasingly inhospitable.

He has been staying in the Knightsbridge flat, which houses the embassy, since 2012 when he fled extradition proceedings at the UK’s supreme court. Swedish prosecutors have since dropped their request to extradite him to Stockholm over a rape investigation.

If he were to walk out on to the street, Assange is likely to face contempt of court charges for fleeing British justice. His chief fear, however, is that once arrested, the US authorities would begin fresh extradition proceedings against him alleging security offences.

It is believed American prosecutors have been investigating Assange since at least 2011, when a grand jury hearing was opened into the whistleblowing website’s publication of hundreds of thousands of US diplomatic cables, in conjunction with a number of international newspapers including the Guardian.

The IACHR monitors human rights in the Americas and hears appeals on individual cases. The Trump administration, however, has boycotted its recent hearings.

The 1,172-page submission by Assange’s lawyers calls on the US to unseal any secret charges against him and urges Ecuador to cease its “espionage activities” against him.

Baltasar Garzón, the prominent Spanish judge who has pursued dictators, terrorists and drug barons, is the international coordinator of Assange’s legal team. He has said the case involves “the right to access and impart information freely” that has been put in “jeopardy”.

The Trump administration is refusing to reveal details of charges against Assange despite the fact that sources in the US Department of Justice have confirmed to the media that they exist under seal.

“The revelation that the US has initiated a prosecution against Mr Assange has shocked the international community”, the legal submission to the IACHR states. The US government “is required to provide information as to the criminal charges that are imputed to Mr Assange in full”.

The application alleges that US prosecutors have begun approaching people in the US, Germany and Iceland and pressed them to testify against Assange in return for immunity from prosecution.

Those approached, it is said, include people associated with WikiLeaks’ joint publications with other media about US diplomacy, Guantánamo Bay and the wars in Iraq and Afghanistan.

Assange’s lawyers say the Trump administration has pressurised Ecuador to hand over Assange, making increasingly overt threats. In December, the New York Times reported that Ecuador’s new president, Lenin Moreno tried to negotiate handing over Mr Assange to the US. in exchange for “debt relief”.

The application also highlights what it says are “espionage operations” against Assange in the London embassy.