A Nigerian man, Oscar Okwurime, was on Thursday found dead in his cell at Britain’s largest detention centre, Harmondsworth removal centre.

Authorities have opened an investigation into the incident, reports UK’s The Independent.

It was reported that Okwurime was discovered lying in his cell at Harmondsworth removal centre by another detainee on Thursday evening.

Tapiwa Furumdi, 24, who is also in the facility told The Independent he heard a voice from the room expressing shock and anger.

“Someone had gone into the room and found a body and started making noise. Apparently he was already dead. I heard something like, ‘This bloody immigration, look what they’re doing to us’,” he said.

He said officers attended the scene quickly, but that “it was quite apparent that he was already dead”. He said it was not clear how he had died.

He described Okwurime as a “quiet guy.” He said “He (Okwurime) kept himself to himself, a really private person. He didn’t talk much at all.

“I don’t think he was happy in here. It’s sad. I felt sorry for the guy.”

Reacting to the death, a Home Office spokesperson said “Any death in detention is a tragic event and our thoughts and condolences are with the family and friends of Mr Okwurime.

“The welfare of all those in our care is of the utmost importance. All deaths in immigration detention are subject to investigation by the police, the coroner and the independent Prisons and Probation Ombudsman.”