An internal Department of Immigration and Border Protection document, seen by Crikey, reveals that the Australian government knew that the Nauruan government was planning to “open” the asylum seeker detention centres on the island before the legislation was even put before Nauruan parliament. Not only that, but the Australian government planned to use the “opening” of the centres as an argument in a case before the High Court — all before the allegedly independent decision by the Nauruan government was made public.

Today is the first of two days of hearings in the High Court for a case challenging whether it is constitutional for the Australian government to be sending asylum seekers from Australia to Nauru to be detained in centres funded, and effectively controlled by the Australian government.

On Friday last week, the government of Nauru announced it would make its detention centres in Nauru “open centres”, with asylum seekers free to come and go, 24 hours a day, seven days a week, and would quickly process the outstanding 600 asylum seeker claims in the next week.

Although the “open centre” arrangement is effectively in name only, with the asylum seekers required to still live in detention centres, and restrictions said to be placed on what they can take in and out of the centre, the Australian government is clearly relying on this new open centre arrangement as part of its argument in the High Court. In an internal document from the DIBP, seen by Crikey, it is stated that on October 1 the Australian government approached the High Court to inform the court about the Nauruan government’s “decision to expand the open centre arrangements”.

Yet the Nauruan government announced on October 2 it was going to put the legislation for an “open centre” arrangement before its parliament, on the same day the Australian government was required to file an affidavit that would be made public revealing the new open centre arrangements.

The government is also not downplaying the significance of the case, according to the internal document:

“This is a significant constitutional challenge in the High Court to the regional processing arrangements, brought against the minister, the Commonwealth, and Transfield … The plaintiff seeks final relief, including orders preventing her return to Nauru, preventing the making of payments by the Commonwealth to Transfield … and declaring she was unlawfully detained by the Minister or the Commonwealth.”

Yesterday it was reported that an officer in the DIBP was internally urging that the department try to return, from mainland Australia, as many asylum seekers to Nauru as possible ahead of the High Court hearing.

Almost as explosively, the document seen by Crikey also reveals that the government is attempting to appeal a landmark Federal Court ruling that the Department of Immigration and Border Protection did not offer a fair process to help asylum seekers whose data the department accidentally published online.

In early 2014 Guardian Australia discovered that the department had had accidentally published the names, nationalities, date-of-birth information, arrival dates, and boat information of close to 10,000 asylum seekers in detention centres on the Australian mainland and on Christmas Island. The information, which was published on the department’s website, was only removed once Guardian Australia alerted the department to the breach.

Dozens of cases have been lodged in the Federal Court asking for those asylum seekers whose data was published to be granted protection in Australia from potential persecution in their home countries as a result of the breach. A number of the claims have been dismissed, but a recent judgment of the full bench of the Federal Court found that in the case of two asylum seekers, the department’s handling of their claims in light of the department’s own data breach had been “unfair to a significant degree”.

After the data breach, the department wrote to those asylum seekers whose details had been compromised, giving them just two weeks to write to the department to explain the personal impact of the department’s data breach. A KPMG report into the incident that included details on the IP addresses of people who had accessed the data while it was hosted on the department’s website was not given to asylum seekers as part of that process, despite the fact that legal counsel for the asylum seekers had sought the report. Asylum seekers were attempting to use the report to determine whether authorities in their country of origin had viewed the document, to be able to determine whether they would face a threat if Australia returned them.

The court found that in the case of the two asylum seekers, the procedures in place to determine their claims after the data breach had been unfair.

“Rare is the case where a decision-maker asks a claimant to make submissions about what should happen in consequence of a failure to adhere to statutory safeguards of confidentiality committed by the decision-maker affecting the claimant,” the three justices said in their judgment.

At the time of the judgment, the department did not say whether it planned to appeal the decision, but in the leaked document, the department has said it will challenge all but one of the findings of the court, and that it filed an application for special leave to appeal the case to the High Court at the end of September. The government will not challenge the court’s finding that then-immigration minister Scott Morrison had been considering lifting the bar, preventing the asylum seeker from applying for a protection visa.

The Department of Immigration and Border Protection confirmed, when asked by Crikey, that an application for special leave to appeal the case to the High Court had been filed, but declined to comment further.