Giving evidence during the second day of the Wikileaks founder’s hearing at the Old Bailey, human rights lawyer Clive Stafford Smith also said that the site’s content had helped to stop drone strikes in Pakistan and provided evidence currently being investigated by the International Criminal Court.

The lawyer, who has represented numerous Guantanamo Bay prisoners, said that the leaked documents had enabled him to win legal actions on behalf of “a number of innocent people in detention” at the U.S.-run detention camp.

He said the leaks had opened his eyes to “torture, rendition and murder” carried out by the U.S. government.

Mr Stafford Smith went on to argue that the scale of new information released by Wikileaks was partly as a result of U.S. authorities’ “obsession with classifying information.”

“When I first went to see a British man in Guantanamo he gave me 30 pages on the torture that he had suffered,” the lawyer said.

“All of this material was immediately classified on the basis that revealing torture was a threat to national security.”

At one point during Mr Stafford Smith’s testimony, Mr Assange tried to intervene from the dock.

The judge warned Mr Assange that this was not permitted and allowed a short adjournment for him to brief his lawyers.

Another expert witness, University of Maryland journalism professor Mark Feldstein, told the court that soliciting leaks was part of a journalist’s “standard operating procedure” and that he had taught related techniques as an academic.

The hearing is being held in line with COVID-19 safety guidelines.

Before the proceedings commenced, 40 civic society groups were promised remote access to the court’s proceedings via a video link.

But presiding judge Venessa Baraitser revoked that permission on Monday, citing fears that the “integrity of the court” could be compromised if the feed was streamed elsewhere.

Reporters Without Borders campaigns director Rebecca Vincent said: “We have never faced such extensive barriers in attempting to monitor any other case in any other country as we have with the proceedings in the UK in respect of Julian Assange.

“This is extremely worrying in a case of such tremendous public interest.”