Australian immigration minister Peter Dutton denies the New Zealand government is being kept in the dark about people being held on Christmas Island.
Australia is holding 200 New Zealanders pending deportation because of new visa restrictions in Australia for those with criminal convictions.
The Iwi n Aus group said about 100 were on Christmas Island and it had been contacted by their families, desperate for information and help.
Speaking after a visit to the centre, Mr Dutton said anybody could return to New Zealand tomorrow if they want, but those appealing against visa cancellation would be held for a prolonged period.