The government says it has not been consulted by Australia about any plans to close the Christmas Island immigration detention centre.
RNZ asked under the Official Information Act for any correspondence between the two governments about such plans, but the Foreign Affairs Minister Murray McCully's office said this information did not exist.
Scores of New Zealand citizensare in the facility awaiting deportation.
The 2016 Budget in Australia indicated the detention centre could be closed by early 2018.
But because at least two mainland detention centres are closing, more detainees are being sent to Christmas Island.
Mr McCully has also refused again to release under the OIA the numbers of New Zealanders held on the island, saying Canberra passed on this information on a confidential basis.