Liridon Saliuka, 29, who was born in Kosovo and held a British passport, was reportedly found unresponsive in his prison cell on the evening of January 2. An investigation has been launched and it’s understood that authorities are treating his death as self-inflicted, which his family disputes.

He’s the third prisoner to have died in Belmarsh in less than a year. A fellow inmate was found dead in the notorious London facility in November.

Saliuka’s family claim there have been delays to the postmortem. His sister, Dita, revealed that her brother was involved in a car crash two years ago that left him requiring major reconstructive surgery. He was given metal plates that made it hard for him to walk or stand for long periods of time.

A report by a surgeon, commissioned by his defense lawyer, had determined that he should be considered as “permanently disabled.” However, his family say he had recently been transferred from a special cell to a standard one.

Belmarsh is also the prison where Assange is currently being held ahead of an extradition hearing. UN Special Rapporteur on Torture Nils Melzer sent a letter to the UK government in December asking it to end the detention of Assange, and warned that his health may soon reach a “critical” stage, including the risk of death.