Manus Island detainees and advocacy groups say the man was seen coming out of a vehicle this morning, hitting the road and dying from his injuries at the scene.

Iranian refugee Behrouz Boochani said the man had a long history of epilepsy.

“Two years ago he was sent to Australia for medical treatment, but they sent him back to Manus again without providing him with medical treatment,” Boochani said via social media.

“He was suffering for a long time.”

Greens senator Nick McKim met the man during visits to Manus Island last year.

“Yet another life destroyed by our government’s punitive policies,” McKim said during a Senate estimates hearing in Canberra today.

The man was also known to the Asylum Seeker Resource Centre.

“This man should never have been there in the first place,” the centre said in a statement.

“This is a catastrophic policy failure that has taken yet another life.”

The UN’s refugee agency said the Australian government must take immediate action to avoid further harm and tragedy.

“With the passage of too many years and the withdrawal or reduction of essential services, the already critical situation for refugees most in need continues to deteriorate,” its representative Nai Jit Lam said.

“Australia’s responsibility for those who have sought its protection remains unchanged. Our thoughts and condolences are with the man’s family today.”

The Department of Home Affairs said in a statement: “The department is aware of the death on Manus Island. Further enquiries should be referred to PNG authorities.”

Papua New Guinea police are now investigating the death – the seventh of a detainee on Manus Island.

– AAP