A vigil for Mr Ahmed outside Immigration Minister Peter Dutton's office on Thursday. All the while, he later told his friends, he was thinking about his wife and little boy, Mazim. The fear became all-consuming in recent months, as his body wilted, his confidence in the detention centre's health providers evaporated and he wandered about the centre at all hours, hoping the exhaustion would bring sleep. When his death was imminent last week, friend Aziz Adam says Mr Ahmed delivered his last message: "If anything happens to me, I need you guys to look after my family." "We will do our best," says Mr Adam, 24, though the Sudanese community on Manus feels incapable of assisting while its members remain in a centre declared unconstitutional by PNG's highest court last April, still unsure whether they will be included in the resettlement deal with the United States.

Mazim, Mr Ahmed's son. What they can do is give their account of what happened to Mr Ahmed, in the hope that it might lead to changes and avert further tragedies. This is why they entered the tent Mr Ahmed shared with 25 others in Oscar compound and took his most precious possessions from the bag by his bed when word of his death began to spread on Christmas Eve. Mr Ahmed who died after being airlifted from PNG. Among them was a cache of requests for treatment by International Health and Medical Services, the global company contracted to provide primary and mental health services to detainees on Manus Island and Nauru.

There were also copies of the formal complaints he lodged against IHMS and Australian Border Force, official responses to his requests and complaints, and personal items including a picture of his wife and boy. At first Mr Ahmed, who spoke little English, had written his requests for help in Arabic, but when time dragged on with little response, Mr Adam says he agreed to translate them into English and read them back to Mr Ahmed before his put his name to them. "It made me feel a human being," Mr Adam told Fairfax Media. "He deserved that kind of compassion and support." Fearing a cover-up, or that the litany of complaints would not emerge until a coroner's inquest a year or two from now, the friends took it upon themselves to put the material on the public record. "We needed to show this is not the way to treat people here," said one of those who took the documents and provided copies to Fairfax Media. "I want everyone to know no one (in authority) cared about him."

Among them is the letter signed by the 60 Sudanese detainees "kindly and humbly" pleading with IHMS to help him after he returned from the clinic and informed friends he had been told there was nothing wrong with him. Two days later, he passed out, fell, hit his head and had a seizure, prompting his transfer to Brisbane, where authorities say he died. The health provider has since released a statement, expressing concern at "the inaccuracies and misinformation" surrounding the reporting of Mr Ahmed's death and pride in the work of its "highly qualified and professional clinicians". "Claims that the patient was denied access to medical care are not correct. He was seen by clinicians and other allied health professionals at the clinic on numerous occasions in the three months preceding his death for multiple issues and his presenting medical issues were assessed, investigated and managed," the statement says. "The facts and circumstances surrounding his death will be referred to the Queensland Coroner. However, currently available information indicates that Mr Ahmed died from severe head injuries sustained in a fall at the Manus Island Regional Processing Centre on 23 December."

Fairfax Media has interviewed several of the detainees who contest the IHMS assertions. They insist Mr Ahmed was the victim of what Dr Barri Phatarfod, president of Doctors for Refugees, has dubbed "a culture of cynicism among at least some of the IHMS health professionals". Dr Phatarfod has provided Fairfax Media with one referral from IHMS for an asylum seeker who had cracked the right lens in his glasses and complained that he could not see out of his left eye. A test had not been done to assess the left eye, the referral asserted, "as they exaggerate their acuity to get attention". Astonishingly, the referral was dated September 7 2014, the day after the life support machine for Iranian asylum seeker Hamid Khazaei, was switched off in the Brisbane hospital. Mr Khazaei died 13 days after presenting at the Manus Island detention centre's medical clinic with an infected foot. A coroner's inquest into his death will reconvene in February. "Faysal was sick and had heart problems for more than six months but IHMS, the company that is responsible for our health, did not care about him and did not provide any treatment for him," says an open letter signed by more than 200 detainees.

What is beyond question is that Mr Ahmed's mental and physical health deteriorated dramatically during his more than three years in detention. Rohingyan refugee, Imran Mohammad, 22, met Mr Ahmed when they were in the same compound in 2013 and says he was "full of life" and very engaging, with no health issues at all. They did not cross paths again until recently, when they were again in the same compound, and Mr Mohammad says Mr Ahmed was withdrawn, had lost a lot of weight and was clearly very ill. "He was a different man," he says. Having survived more than 10 years as an internally displaced person in Sudan and witnessed all manner of horrors, Mr Ahmed began to fall apart on Manus after his claim for protection was accepted in October 2015, some eight months after his "initial positive assessment". The chest pains, stomach aches, dizziness and breathing difficulties became more pronounced in the last six months, after Mr Ahmed learnt that his mother had died in the Sudanese refugee camp.

In his application for protection, Mr Ahmed told how his village was attacked by the militia in 2003. "Around 35 people were killed during the attack including my brother, Abubakar, my grandmother and my uncle. My uncle was slaughtered by the militia when he refused to give up his camels." The family escaped to a refugee camp where Mr Ahmed lived with surviving family members until he fled in July 2013. "It was not safe in the camp," he explained in his application for protection. "On many occasions the Janjaweed militia entered the camp and killed people… They raped my uncle's daughter. My sister was also raped. In one occasion in 2003, I was handcuffed and tied to a tree for two or three days. I was beaten badly. I have a scar on my left forearm where the handcuff was and scars on my forehead where I was whipped. "The militia wanted me to join them as a fighter but I refused." Mr Adam says all the Sudanese refugees have similar stories. "All of us in the Sudanese community living on Manus Island detention centre, we have been experiencing the same trauma and torture, the same nightmares. We prefer not to talk about it because it's painful."

Now they are devastated. "This is Christmas and we were hoping for a gift from the Australian government, like our freedom. All we got was a dead body," he says. When Mr Khazaei died in 2014, then immigration minister Scott Morrison said his department's chief medical officer would be conducting an "in-depth clinical review" of the Iranian's medical treatment while on Manus Island. This time the only official comment has been a brief statement on the Border Force website, saying the department is not aware of any suspicious circumstances and the death will be reported to the Queensland Coroner. Those still detained say this is not good enough and, in their open letter, have called for a royal commission to investigate Mr Ahmed's death. One of those still detained is the Iranian Kurdish journalist Behrouz Boochani, who recalls that a similar open letter was written at the time of Mr Khazaei's death, and that it concluded by asking who the next victim would be.

Mr Ahmed was among those who put his name to the letter. Follow us on Twitter