News today that the Immigration Health Advisory Group (IHAG) no longer to exist is not to be taken lightly. The independent body of psychiatrists, psychologists, GPs and other medical professionals and advocates gave advice to the government about the serious mental health impacts of offshore processing and long term detention – and the group's dismantlement is the latest announcement by the government which builds a veil of secrecy around its handling of refugees.

Despite the best efforts of advocates and journalists, the workings of Australia's offshore processing policy, including Australia’s detention centre in Papua New Guinea, continue to remain largely hidden. With the Australian government’s implementation of Operation Sovereign Borders, information on asylum seekers arriving by boat has been even more closely guarded.

Our latest Amnesty report is based on the most up-to-date, accurate information gathered during our visit some three weeks ago now. So despite claims by the Australian government and PNG foreign minister Pato that the information is inaccurate and out of date, this is simply not the case – and the public has a right to know.

We also know that, in the 12 months since offshore facilities reopened, they have cost the Australian public well over $1bn and in that time only one asylum seeker has undergone the full refugee status determination process. So what is our money paying for?

The impression, both to me and many asylum seekers we spoke to, is of a combination of a prison and a military camp. The detention centre is made up of single-storey buildings for staff and several “compounds” that house asylum seekers, all divided by fences of about 2.4 metres in height and connected by uneven dirt tracks. Asylum seekers are prevented from leaving by locked gates and security guards at the exits to each compound and the main entrance to the facility.

There are currently around 1,100 asylum seekers detained in the facility, from countries such as Afghanistan, Burma, Lebanon, Iran, Iraq, Pakistan, Somalia, Sudan and Syria. Some, such as the Rohingya from Burma, are denied a nationality or citizenship. The stories they told us, of the situations they had fled, were as varied as the men themselves but frequently reflected is already known about serious human rights abuses in those countries. The only common thread was that each man had tried to reach Australia by boat.

Over the course of the week, through interviews and inspections, we built a picture of daily life in detention on Manus.

The living conditions in the facility are hot, extremely cramped and poorly ventilated. There is no privacy. The conditions in one dormitory were so bad that Amnesty International considers the accommodation of asylum seekers there a violation of the prohibition on torture and other ill-treatment. "P Dorm" is a World War II building with a low, curved, metal roof. It sleeps 112 men on bunk beds arranged with no space between. There were no windows, and two standing fans. As a result, the smell is overwhelmingly bad and the heat is stifling. Asylum seekers reported finding snakes in the room and flooding when it rained.

As the week progressed, we witnessed a string of unnecessary humiliations.

The men spend several hours each day queuing for meals, toilets and showers in the tropical heat and pouring rain, with no shade or shelter. Staff refer to them by their boat ID, not their names. Almost all are denied shoes. Most have had their possessions confiscated by people smugglers or staff on Christmas Island.

The 500 men in the "Oscar" compound each receive only 500mls of water per day, though the recommended quantity is five litres each. In Oscar, there is one toilet for every 30 men and they are often dirty or broken. The men are not given enough soap, shampoo, mosquito repellent, washing powder or shaving equipment. Contact with loved ones by phone is limited to two 15 minute calls a week, strictly regulated, often in the middle of the night with no privacy. Despite the difficulty connecting, men calling their families in remote areas or war zones are given no extra time – when your 15 minutes is up, it’s up.

The men, most under 35, have almost no activities to keep them occupied. In one dormitory, we were led by an asylum seeker to the back of the room. He jumped over a bed into a small space covered by sheets between two sets of bunk beds. On the sheet the man had drawn a large television, DVD player and games console. Using strips of bed sheet, he had made two electrical cords, at the end of which were two games controllers made from cardboard, with buttons drawn on them. He said, “We use this to pass the time. It is no laughing matter. We pretend to play and it brings back memories of home."

The facility is unable to provide suitable treatment for men with serious illnesses and disabilities – which include asthma, diabetes, epilepsy, gastroenteritis and dwarfism. Staff told us that they’re struggling to cope with the growing demand for health and mental health services, and they receive no response from the Australian authorities to basic requests which would improve health and sanitation within the camp.

With no processing, no information and a daily routine of appalling conditions and humiliations, the pressure on asylum seekers to return is enormous. Perhaps worst of all, the men have no idea what is happening to them – they don't know how long they will be detained in these conditions, or what their future life in PNG might be.

One asylum seeker told us, “We just need to have some certainty. I have lived in war zones, with bombs and explosions. I have never experienced what I am experiencing here with the uncertainty we face. If we had died in the ocean, that would have been better. I just need to know my destiny so that I can sleep at night. Just to know, so I can be prepared for what will happen.”