New figures show the time asylum seekers spend in Australian immigration detention on Nauru and Manus Island has hit a record high - an average of 446 days.
The Department of Immigration and Border Protection statistics show the wait time has increased steadily since May 2015, and is more than double than that under the Labor government.
It also shows nearly a quarter of detainees spend more than two years in the centres.
The Asylum Seeker Resource Centre's detention rights advocate, Pamela Curr, says leaving people in detention for long periods of time is part of the government's deterrence policy.
"We have got people in detention now who are refugee positive, that means they have gone through the process, they have been found to be refugees, they have been security cleared, they have been health cleared - all that is required is that the minister signs their release document. And successive ministers are refusing to do that."
Ms Curr says those in detention for long periods of time are suffering mentally and physically.
She says the conditions at the camps are becoming more punitive, and the ASRC continues to receive reports of beatings and sexual assaults.
"We saw last week children who are now being forced to go to the local school because the camp school has been closed down - a little five-year-old was urinated on by a gang of Nauruan kids. We see reports of refugee children being harassed for sexual favours."