A young girl who spent nearly two-and-a-half years in detention on Christmas Island may have been falsely imprisoned for part of that time, lawyers have alleged after obtaining documents under freedom of information.

The former Labor immigration minister Tony Burke moved the girl with her family to Darwin for medical reasons shortly before the 2013 federal election and determined that they should be released into the community. But that decision was apparently reversed after the Coalition won government.

The girl, referred to as AS, who is now eight, suffered from serious medical and dental issues, which her lawyers allege were “poorly treated”.

The documents form part of an updated legal file by lawyers running a class action against the federal government for the treatment of people held on Christmas Island between August 2011 and August 2014. They will now also ask the Victorian supreme court to consider whether the girl and her family were falsely imprisoned.

On 2 September 2013, Burke tabled a statement that said he had determined three families would be moved from immigration detention into the community, because of their “individual circumstances” and because it was in the public interest. At the time the three families, including AS’s, had been temporarily transferred to Darwin. AS’s mother was about to give birth.

The immigration department advised Burke there were no security concerns with the families.

A 2016 departmental email noted the approved release was “part of the change of government push for the 2013 election”.

“This was when the department was advised by the minister of the day that all UAMs [unaccompanied minors] and families with children were to be to moved into community detention in a short time frame [10 days].”

The email said a referral was received on 23 August for the family’s transfer and no ministerial intervention was received that might have prevented it. But the government changed after the election on 7 September.

The family was not released for another 15 months.

“We draw the conclusion minister Burke had authorised the family to go into community detention and we’ve seen nothing that revokes that,” the principal lawyer for Maurice Blackburn, Jacob Varghese, told Guardian Australia.

“We’re concerned as well that there was no lawful authority to hold them in detention … There would have to be some sort of similar document from the next minister revoking it.

“We’ve been asking for it and it never turned up.”

The lawyers had been examining alleged failures by the federal government and the immigration minister to provide adequate healthcare for children seeking protection in Australia, before the addition of the false imprisonment question.

“We’re challenging the conditions in which people have been held in detention,” Varghese said. “The prolonged detention obviously raises the standard of care you’re going to have to provide.”

Varghese said the government was “fighting hard” in the case.

“The Department of Immigration has sought to stonewall this case every step of the way, forcing Maurice Blackburn to seek court orders for access to the facilities on Christmas Island and to endure a prolonged fight to gain access to whistleblowers who feared prosecution under the Border Force Act,” he said.



“In our view there are a number of very important questions that need to be answered by the commonwealth government and the minister for immigration with respect to these events.”

In December the court granted witnesses in the case exemption from the secrecy provisions of the Border Force Act, which carry penalties of up to two years’ jail for the disclosure of “protected information” by “entrusted persons”.

The family in question was later released following another court case on behalf of more than 100 babies born in detention, including AS’s brother.

The immigration minister has been contacted for comment.