The WikiLeaks founder (pictured), who was holed up in the Ecuadorian embassy in London for seven years, is wanted over leaks of classified military documents

Julian Assange's fight against extradition to the US could last six years and cost British taxpayers £600,000, it was claimed yesterday.

The WikiLeaks founder, who was holed up in the Ecuadorian embassy in London for seven years, is wanted over leaks of classified military documents.

The 48-year-old Australian was arrested in April when police dragged him from the embassy. He is now being held in a London jail awaiting an extradition hearing next year.

Mr Assange sought refuge at the embassy after being accused of sexual assault in Sweden.

His stay is thought to have cost the UK £16million in policing and other expenses. The charity Blueprint for Free Speech told The Times: 'He will fight this as long as it takes.

'That could be all the way to the Supreme Court and to [the European Court of Human Rights in] Strasbourg if need be.'

The 48-year-old Australian was arrested in April when police dragged him from the embassy. Here he is pictured in a prison van leaving Southwark Crown Court in London in May

It is thought the US has assured Britain Mr Assange will not face the death penalty if he is extradited.

At a hearing today the case against him will be set out before a full hearing in February.

But if the case goes to a series of appeals, Mr Assange could remain in a UK jail until at least 2025.

It is estimated jail and court costs would run to nearly £600,000 over that time.

He is understood to be in solitary confinement now after a video of him taken by an inmate was posted online.