People hold placards at a protest againt the Nauru detention centre outside an immigration office in Sydney Getty

Amnesty International has described the alleged abuse occurring in Australia's controversial offshore detention centre in Nauru as "one of the most successful mass cover-ups" of human rights violations of all time. More than 8,000 pages detailing incidents of sexual abuse, self-harm, assaults and unsafe living conditions have been leaked detailing a "system of routine dysfunction and cruelty" at the asylum centre in the Pacific island.

More than 2,000 incident reports, published by the Guardian, reveal that more than half the allegations of abuse at Nuaru involve children, despite them making up only around 18% of the population during the time covered by the reports of May 2013 to October 2015.

In total, there are 59 reports of assault on children, 30 of self-harm involving children and 159 of threatened self-harm involving children at the camp.

Among some of the incidents, ranked from minor to critical, include frequent threats of suicide by refugees, staff members slapping and threatening to kill children at the camp and an incident where a "young person had sewn her lips together" which officers were seen laughing about. In other incidents, a minor was found to have sewn a heart shape into her hand using a needle and thread and a woman slashed her wrists using a sharpened pencil.

One guard was alleged to have put his hands in the pants of an asylum-seeker child during a car trip, in which her father was present, and one young girl was reported to have said a male asylum seeker had sexually assaulted her by "cut[ting] her from under" in 2014. There are dozens of reports of young girls being assaulted by other children inside the camp and one woman made a claim of sexual assault after being found walking naked through the community.

Another woman was told she was "on a list" of single women that Nauruan guards were "waiting for" and had "received offers to get her pregnant" when she left the detention centre. One woman was also said to have been told "If that happened to you why didn't you scream at the time?" when she attempted to describe a sexual assault allegation at the camp.

The conditions of the camp were also revealed to be unsafe for humans to live in, with toilets in unsanitary conditions. One guard also allegedly shone her torch on a girl's genitals while she attempted to urinate in an open toilet.

Nauru migrants Australia refugee
Conditions at the Nauru Regional Processing Centre have previously been described as unsafe by a group of Australian Senators UNHCR

Amnesty International, who had previously detailed the extent of the abuse of asylum seekers at the camp, describe the incident report leak as "dizzying in its scale and utterly damning for the Australian authorities who tried so hard to maintain a veil of secrecy".

Senior Director for Research Anna Neistat said: "When Amnesty International and Human Rights Watch went to Nauru against the odds and saw with our own eyes the appalling and systemic abuses taking place, the Australian government tried to roundly deny our findings.

"Australia's offshore processing of refugees must end, and all of the refugees and asylum seekers on Nauru and Manus Island must be resettled immediately and given the medical and psychological support they need. It is clear from these documents, and our own research, that many have been driven to the brink of physical or mental breakdown by their treatment on Nauru.

"The Australian government has engaged in one of the most successful mass cover-ups I've witnessed in my career of documenting human rights violations. They've repeatedly said this kind of abuse has not been going on. They've been lying.

"The exposure of just how appalling the conditions on Nauru are – and the impact of this on refugees – has to end the government of Australia's denials."

Conditions at the refugee camp was previously condemned as unsafe by an Australian Senate committee, describing the Nauru camp as "neither a safe nor an appropriate environment for children and that they should no longer be held there".

Australia's Prime Minister Malcolm Turnbull has called for an investigation into how the allegations of abuse at Nauru had been dealt with.

A spokesperson for the Department of Immigration and Border Protection said: "It's important to note many of these incident reports reflect unconfirmed allegations.

"They are evidence of the robustness of reporting procedures under which any alleged incident must be recorded, reported and where necessary investigated. Many of the specific examples and cases quoted in the reports have been the subject of extensive previous media coverage and reporting by the department.

"The department is seeking urgent advice from its service providers today to confirm all of these matters have been previously and appropriately reported to it, consistent with the policies and procedures covering such matters."

Sleeping conditions seen inside the detention camp Amnesty International