Nauru's former chief justice, Geoffrey Eames, says New Zealand and Australia have trivialised a serious breach of the rule of law in Nauru.
Mr Eames has resigned from his post two months after being barred by the Nauru government from returning to the country.
Nauru also deported the resident magistrate and other expatriates, making allegations of cronyism.
Mr Eames says New Zealand was in a very strong position to get Nauru to acknowledge it had departed from important principles as it is a major source of funds for the judiciary.
Instead he says New Zealand and Australia initially put out statements saying the controversy was a matter of domestic politics.
"It was a very great deal more significant than a mere dispute over detail. It was an absolutely fundamental core issue about the nature of the government, whether it was applying a democracy and whether it accepted the rule of law."
Mr Eames says strong condemnation of the Nauru government from Pacific chief justices shows the seriousness of the breach.