Julian Assange's father attended a London court today to see his son appear via a videolink from high-security Belmarsh prison.

A court hearing was held at Westminster Magistrates Court this morning ahead of what it expected to be a long-running extradition battle to get for Wikileaks founder to the U.S.

His father, John Shipton, was among supporters in the court's public gallery, who saw Assange appear on a TV monitor.

Julian Assange's father John Shipton at Westminster Magistrates' Court in London today, where the Wikileaks founder appeared via videolink

Assange, pictured in a prison van on his way to jail in April, faces extradition to the U.S. over leaking government secrets. The legal battle over his extradition is expected to last months, if not years

The 48-year-old WikiLeaks founder is accused of leaking US government secrets in one of the largest breaches of confidential information.

Assange wore a grey prison-issue jumper and thin-rimmed glasses and spoke only to confirm his identity. His white hair slicked back and appeared to have stubble.

Gareth Peirce, representing Assange, told the court that her client was unable to adequately prepare for his 'very challenging case' as the computer he had been given was not suitable.

Ms Peirce said: 'I will put it on the record, you will understand that we are working extremely hard on this very challenging case; however, the most important of the impediments that we are facing is Mr Assange's ability to access what he needs to work on his own case.

'After months of battle he was provided with a computer but it is not the sort of computer needed to work on the case.'

District Judge Vanessa Baraitser said she had no jurisdiction over the prison conditions. She extended Assange's remand in HMP Belmarsh.

Mr Assange Snr has previously complained about his son's treatment in Belmarsh prison

He was set to be released from the high-security prison in September but was remanded in custody due to fears that he would abscond after he spent nearly seven years in the Ecuadorean embassy in London.

Speaking outside court, a member of Assange's team said hat the computer was unlikely to have internet access needed for research.

District Judge Baraitser remanded Assange in custody ahead of a substantive case management hearing on December 19.

He will appear again at Westminster Magistrates' Court on December 13 to confirm his remand in prison again before he ultimately appears for full extradition proceedings in February.