Julian Assange has been blocked from seeing evidence in his extradition case as he battles against being sent to the US, a court has heard.
Lawyers representing the WikiLeaks founder told a hearing they were not being given sufficient access to their client in prison.
Mr Assange appeared at Westminster Magistrates' Court via a video link on Friday for the hearing, which was about extending his custody at HMP Belmarsh.
Defence lawyer Gareth Peirce said Mr Assange's legal team was struggling to prepare documents for the case because their client had no access to the evidence.
“Without Mr Assange's knowledge, some of it is recently acquired evidence, some of it is subject to months of investigation not always in this country, of which he is unaware because of the blockage in visits,” she said.
“Despite our best efforts, Mr Assange has not been given what he must be given, and we are doing our utmost to cut through this.”
Ms Peirce said the governor of HMP Belmarsh had prioritised family visits over legal visits and asked the judge to step in.
But the district judge Vanessa Baraitser said she had no jurisdiction over the prison service.
“I have no desire to stand in the way of any lawyer having proper access to their client and it's in the interest of justice that they do,” she said.
“What I can do and say is to state in open court that it would be helpful to this extradition process that Mr Assange's lawyers have the access to their client.”
Mr Assange is being held in prison ahead of a full hearing in February when he will fight extradition to the US.
He faces 18 charges, including conspiring to hack into a Pentagon computer.
Mr Assange is accused of working with former US army intelligence analyst Chelsea Manning to leak hundreds of thousands of classified documents.
With unkempt white hair and beard, he appeared uncomfortable as he sat waiting for the hearing to start, clenching his hands together before putting them inside the sleeves of his grey jumper.
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