The Nauru Government is limiting a defendant's access to overseas lawyers.
The Nauru practitioners' law, passed last week, means overseas lawyers working on a pro bono basis can only be involved if they have been instructed by a local lawyer or pleader with more than 10 years' experience on Nauru.
An Australian lawyer who has Nauru registration, Stephen Lawrence, said the move could severely limit access to justice for people on Nauru.
"It may well be the case that there are no pleaders willing to appear on a pro bono basis who have more than 10 years experience. So I think this law, in a number of respects, will pose real challenges to meaningful access to justice on Nauru."
Last year the Nauru Government moved to redefine contempt of court as anything that scandalised a judge, a court or the justice system in any manner whatsoever.
This prompted the New Zealand Law Society to say Nauru was sliding towards authoritarianism.
A year earlier the government was accused of judicial interference when it attempted to stop the right to subpoena government employees to appear as witnesses in court.