22/05/2016 1:36 PM AEST | Updated 15/07/2016 12:52 PM AEST

Nauru, Manus Island Detention Inflicts 'Psychological Torture'

World Vision's Tim Costello has weighed into the asylum seeker debate.

The Greens support the World Vision boss' criticism of offshore detention.

The Australian Greens have backed comments by World Vision boss Tim Costello who says detaining asylum seekers offshore constitutes psychological torture.

Costello on Sunday said there was "no question" about the mental torture inflicted on those unable to find a permanent home.

"The psychological torture of not being able to actually resettle, and you can't go back home, is torture," he told Sky News.

Mr Costello reportedly said a Somalian woman who set herself on fire on Nauru demonstrated the impact the federal government's refugee policy on those in detention.

Speaking in Adelaide, Senator Sarah Hanson-Young said Costello was correct and that offshore processing should end.

"We need to close these camps and reinvest that money into assessing people's claims in Indonesia and Malaysia, help the UN to assess those claims and then bring people here safely," she said.

"We don't need these hellholes to remain open. We need them to close and we need to put in place a safer and more humane system."

Opposition Leader Bill Shorten conceded that Costello 'has a point' and accused the government of delays in resettlement.

"In terms of what Tim Costello is talking about in the cost and the pain and the suffering of indefinite detention, I think he has a point.

"As prime minister, I would prioritise regional resettlement. The answer to defeating the people smugglers cannot be indefinite detention. That is what the government is pushing.

"The truth of the matter, this government has let delays blow out. They have not been transparent in terms of the treatment of people in our care. I sympathise with what Tim Costello is saying.

"The best answer is to defeat the people smugglers and make sure that the people in our care, directly or indirectly, get proper resettlement."

However the Prime Minister, Malcolm Turnbull, rejected Costello's comments while addressing reporters in his electorate.

"It is absolutely critical that we maintain a secure border protection policy," he said.

"That is why it is absolutely critical that people who seek to come to Australia through the services of people smugglers are not able to settle in Australia."