Visa costs a revenue measure, Nauru says

Nauru says its decision to dramatically increase the cost of media visas is a revenue measure.

A spokeswoman for the tiny island nation, which hosts a controversial Australian immigration detention centre, has confirmed the cost of a media visa is set to increase from $200 to a whopping $8000.

Labor and the Greens have questioned whether the increase is designed to deter Australian reporters from visiting the detention centre, linking it to the Abbott government's secretive approach to asylum seekers.

But the Nauru government spokeswoman says the change, which is yet to come into force, is solely for "revenue purposes".

Asked whether the Australian government requested the change, the spokeswoman told AAP: "I haven't been told anything to suggest that."