The move has upset former MPs having pending appeals and triggered calls for Australia and New Zealand to tend to what is being labelled a constitutional crisis.
Nauru president, Baron Waqa, spoke about the proposed change last month, telling parliament that establishing a court of final appeal on Nauruan soil was an “affirmation of Nauru’s sovereignty, independence, and maturity as a nation”.
The Australian Department of Foreign Affairs and Trade confirmed that Australia was notified of the termination on December 12, meaning the 90 day period concluded on 12 March.
A former justice minister Mathew Batsuia, who is one of 19 people with appeals pending in court, said the action was an outrage.
Batsuia said any termination of the arrangement with Australia had to be approved by a two-thirds majority in parliament which he said was not due to sit until later this month.
A replacement court is yet to be constituted.
An Australian human rights lawyer and adjunct professor George Newhouse accused Foreign minister Julie Bishop of being complicit in stripping the people of Nauru and asylum seekers of their legal rights.
He said Australia was sending asylum seekers to an island prison where they had virtually no rights, if rights of appeal to the High Court were taken away.
He also said the Prime Minister of New Zealand Jacinda Ardern needed to step in to ensure that the rule of law in Nauru was protected as New Zealand held an important leadership role in the Pacific.
In January 2014, the Nauru government expelled the country’s only magistrate and refused to allow the then Chief Justice back into the country.
As a result, the New Zealand parliament passed a motion expressing concern about the rule of law in Nauru, and Wellington stopped funding the justice sector in Nauru.