He spoke to confirm his name, date of birth, and nationality.

Mr Assange’s lawyers have previously complained that he had been given access to an unsuitable computer in prison, while doctors have raised concerns over his health and fitness to stand trial.

Mr Assange has been in custody since he was dramatically removed from London’s Ecuadorian embassy in April. At a hearing in October, he appeared to struggle to say his own name, telling Westminster Magistrates’ Court: “I can’t think properly.”

He was jailed for 50 weeks in May for breaching his bail conditions by going into hiding to avoid extradition to Sweden over sex offence allegations in 2012.

Last month, Swedish authorities dropped their investigation into those allegations, which Mr Assange had denied.

He will next appear in court on Thursday for a case management hearing.

Additional reporting by PA