One in four refugees locked in indefinite detention have attempted or threatened suicide, with high rates of depression, anxiety and self-harm, The Age has reported.

The report reveals 44 refugees have been assessed by ASIO to be threats to national security, with several detained for more than five years without charge.

• Settled Nauru refugees speak out
• Asylum seekers to be released
• ANALYSIS: Why Australia is failing on asylum seekers

None of the refugees are allowed to know the detail of the assessments used to justify their incarceration, leading to a heavy psychological toll and high rates of self-harm.

The 42 men and two women have been recognised as refugees, but are being held in a legal limbo that their lawyers are saying is similar to that of Guantanamo Bay. 

The United Nations found last August that Australia’s policy of indefinitely holding refugees with adverse security findings was in breach of international law.

At least two-thirds of the group have needed counselling or medication for depression, with at least 11 attempting or threatening suicide.

Most are believed to be Tamils who fled Sri Lanka’s civil war, which ended in 2009.

Sydney University law professor Ben Saul, who was responsible for taking the case to the UN, described the detention as inhumane.

“This is our Guantanamo, a legal black hole of indefinite detention that is beyond the rule of law [and] fairness,” Professor Saul said.