The president of the court in French Polynesia has decided to move the case brought by the pro-independence leader Oscar Temaru against the prosecutor Herve Leroy to New Caledonia.
Mr Temaru had sought a preliminary ruling claiming Mr Leroy had violated the assumption that he was innocent.
He said the prosecutor had asserted that he was convicted of a crime while the trial process had not been concluded.
After two deferrals within nine days, the court found it could not deal with the case with full impartiality and ordered it to be moved to Noumea.
Mr Leroy's lawyer wanted the affair to be transferred to Paris.
No date has been set for a hearing.
Mr Temaru reacted to the decision by saying several Kanak tribes would welcome him.
New Caledonia's borders are closed because of the Covid-19 pandemic except for returning residents and some French officials.
There are currently no flights between Papeete and Noumea.
There are suggestions the proceedings could be done via video.