The Nauru government has told United Nations human rights investigators not to go there.
The cancellation of the sheduled trip to investigate the treatment of asylum seekers Australia sends to Nauru is understood to have originated in Canberra.
The UN delegation has been in New Zealand looking at this country's human rights record and planned to go to Nauru next.
But its leader, Mads Andenas, says the trip has been called off.
"The government of Nauru which invited us have asked us not to come. They cite practical reasons for it not being suitable, practical for us to come."
Mads Andenas declined to comment on the conditions on the island without being able to go there.