There are reports Hamid Kehazaei, a 24-year-old Iranian asylum seeker who had been detained on Manus Island, has been declared 'brain dead' after suffering a heart attack.

According to the Refugee Action Coalition, Hamid Kehazaei was transferred to the mainland on August 27 to receive urgent medical treatment in a Brisbane hospital.

He was suffering from septicaemia developed from a cut in his foot, and was admitted into intensive care at the hospital where he suffered a heart attack.

Septicaemia occurs when disease-causing bacteria enters the bloodstream.

Yesterday, the Immigration Department and the hospital informed Mr Kehazaei's family that he has been decared brain dead.

The hospital told his family a legal guardian will be appointed to make the decision about the withdrawal of life support.

Mr Kehazaei formed part of the first group of asylum seekers transferred to Manus Island by the then Labor Government in September 2013.

Refugee advocates say in the last few days 'P block' in the Foxtrot compound where Hamid and 140 others were living has been evacuated and closed.

“Hamid is a victim of the shocking conditions and medical neglect on Manus Island. It is inexcusable that he developed septicaemia on Manus Island,” Ian Rintoul, spokesperson for the Refugee Action Coalition, says.

Mr Rintoul says the Australian Government is responsible for the conditions that led to Mr Kehazaei's illness.

"There are scores of infections on Manus Island, and many complaints of the lack of medical attention. Asylum seekers on Manus Island are often forced to walk through raw sewage."

Fellow asylum seekers being detained at Manus Island detention centre signed a letter declaring the International Health and Medical Service (IHMS) is to blame for Mr Kehazaei's condition. IHMS is contracted by the federal government to run health services within Australian detention centres.

Victoria Martin from Refugee Rights Action Network in Perth has been in written communication with asylum seekers in detention on Manus Island.

They told her Mr Kehazaei was sick for days and they believed he was not receiving adequate treatment before he was transferred to Brisbane.

"It is often the case that asylum seekers have to go through non-medical staff to get access to medical services," Ms Martin says.

"One person said to me, when they took him out of the compound he was already in a coma."

A spokesperson for the Minister for Immigration and Border Protection told SBS: "In respect to the family of the individual further details are not able to be provided."

“The government is following normal processes for the adult male transferee. The family has been engaged.”