WikiLeaks founder Julian Assange cannot be extradited to the US, a judge at the Old Bailey has said.

Judge Vanessa Baraitser said she had refused his extradition because of fears that he could commit suicide.

The Australian activist, 49, faced an 18-count indictment alleging a plot to hack computers and a conspiracy to obtain and disclose national defence information.

He was re-arrested in September over new charges contained in a US indictment.

It alleges that he conspired with army intelligence analyst Chelsea Manning to crack a scrambled password, known as “hash”, to a classified US defence department computer.

The charges also offer further details of alleged hacking plotters that Assange and his WikiLeaks colleagues are said to have recruited.

Assange denies plotting with Manning to crack an encrypted password on US Department of Defence computers and claims there is no evidence anyone’s safety was put at risk.

He appeared at the Old Bailey on Monday where Judge Baraitser delivered her judgment on whether he should be extradited to face the charges in the US.

WikiLeaks editor-in-chief Kristinn Hrafnsson described the case as “an historic, large-scale attack on freedom of speech”.

Assange’s fiancee, Stella Moris, with whom he has two young sons, was at the Old Bailey for the hearing.