Law firm Maurice Blackburn filed the action in the Victorian Supreme Court on Tuesday on behalf of the girl and potentially hundreds of asylum seekers and refugees who claim to have been injured while housed on Christmas Island over the past three years.

The minister, Scott Morrison, his department secretary Martin Bowles and the Commonwealth have been negligent in providing health care for Christmas Island detainees, the action will claim. It will seek an order that detainees are moved to a place where they can receive health care, including specialist mental health treatment.

Jacob Varghese, Maurice Blackburn principal leading the case, said there were 334 asylum seekers on Christmas Island, including 148 children. He said Christmas Island had a mental health crisis. He said children, adults, pregnant women and people no longer on Christmas Island could join the claim.

The girl, known in the court as A.S., has lived on Christmas Island for just over a year. She arrived with her parents but was separated from her mother soon after arrival when her pregnant mother was transferred to the mainland to have her baby. The girl and her father remained and she developed serious separation anxiety, including stammering, bed wetting and waking up to three times a night in distress to make sure her mother is still in the room. She is also refusing food.

Katie Robertson, social justice lawyer with Maurice Blackburn, has twice visited Christmas Island where she met A.S. She said A.S's ongoing dental infection remained untreated for three months. She has been on a waiting list for her stammering for about a year. Ms Robertson said she had been diagnosed with post traumatic stress disorder and anxiety.

"When I met with her about a month ago she struck me as an extremely sad and disturbed child," Ms Robertson said.

Mr Varghese said he was aware of 11 detainees who had attempted suicide due to depression, but had received "nothing but suicide watch", often a male guard watching a woman detainee for 24 hours a day.

"That stops the suicide but does nothing to treat the underlying problem, in fact, it makes it far worse. What people need is sympathetic and compassionate intervention," he said.

Mr Varghese said compensation could only offer a "small measure of justice" but would help them rebuild their lives once they were free.

"We can't, through compensation, give people back the years they have lost while in detention and we certainly can't give children back their childhoods which have been robbed from them," he said.

He said the class action was designed to bring the government to account and allow injured asylum seekers an opportunity to tell their story.

"That's important for them but that is also important for Australia. At some point our country needs to understand exactly what our government has been doing on Christmas Island," Mr Varghese said.

Sister Brigid Arthur, of Albert Park, will act as the litigation guardian for the injured detainees. She said she had not been to Christmas Island but had visited detention centres for 13 years. Mr Varghese said her role would be to ensure the lawyers acted in the interest of the litigants and to provide instructions on the litigants' behalf.

"I think we know - and that we can never claim we don't know - that this has had an extremely bad effect in all sorts of ways on individual people," she said.

"I have watched kids just deteriorate in terms of their obvious wellbeing. Looking at them as ordinary little kids skipping around, to kids who can't look at you. Who look sad and often won't come out of their rooms to actually see you," she said.

The court proceedings come as Mr Morrison told the Australian Human Rights Commission inquiry into children in detention that more than 30,0000 asylum seekers, including those on Christmas Island, would not be offered a visa until the Senate passes controversial temporary protection visa laws. While the visa does offer work rights, it does not allow asylum seekers to stay permanently in Australia.

The temporary protection visas have been widely criticised by human rights advocates as being cruel and degrading to asylum seekers since it was first introduced by the Howard government in 1999.

Greens immigration spokeswoman Sarah Hanson-Young, called for the government to release all children in detention immediately.

"Instead of destroying children and being forced to pay compensation, the Abbott government should release them into the community immediately," said Senator Hanson-Young.

with Sarah Whyte

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