The Nauru Government says it dismissed its resident magistrate because it lost confidence in his ability to hear matters in a fair and equal manner.
Magistrate Peter Law was sacked on Sunday and deported back to Australia while Chief Justice Geoffrey Eames' visa has been withdrawn.
In a statement, the government says it received a number of complaints against Mr Law before his termination.
It alleges those complaints included inappropriate behavior towards staff, drunk and disorderly behaviour, allegations of interfering in cases and advising aggrieved parties on how to conduct their cases.
It also alleges complaints of undermining senior public servants, and exclusion of certain members of the judiciary staff from needed training.
The government says it was appropriate that Mr Law leave Nauru as soon as possible before any more damage could be done to the reputation and good standing of the Nauru judiciary.
However, Peter Law has earlier said ministers were unhappy with injunctions he granted against the deportation of three business people.