Christian Tein is the leader of an independence advocacy group that claims French officials played a leading role in weeks of violence that broke out in May.
Thein appeared in court in New Caledonia’s capital Noumea on Wednesday along with 10 other people arrested in the French Pacific territory.
Local media reported that the 11 people appeared before prosecutor Yves Dupas on Saturday morning.
Dupas launched a judicial investigation and ordered Thein held in pre-trial detention in mainland France, about 16,800 kilometers from New Caledonia.
Thein is the leader of the Field Action Coordination Cell (CCAT), an independence movement group calling for an end to French rule in New Caledonia.
The 11 people are suspected of being involved in the deadly violence that has swept the archipelago, where indigenous Kanak people have long sought to break away from France.
The detentions are part of an ongoing police investigation since May 17, just days after the unrest first broke out, with armed clashes, looting, fires and other violence turning Noumea and parts of its suburbs into no-go zones. .
The mutiny led France to declare a state of emergency in the archipelago and rush in reinforcements to support its quickly overwhelmed police force. The violence left nine people dead, including two military police officers, and caused widespread destruction of shops, businesses and homes.
Prosecutors last week said the detentions were part of a police investigation into a wide range of alleged offences, including conspiracy to commit murder, attempted murder, armed robbery, arson and membership in a group designed to prepare for acts of violence.
As France now plunges into a frenzied campaign for snap parliamentary elections, French President Emmanuel Macron has halted reforms that would transform New Caledonia’s voting rights.