French police in New Caledonia have released the leader of the CSTNC union, Sylvain Nea, who had been held in custody for 36 hours following complaints about disturbances during a recent three-week strike.
Mr Nea was held at the Noumea police headquarters while his supporters maintained roadblocks on the streets outside.
New Caledonian television says journalists trying to film the scene were prevented from doing their job.
As part of the strike campaign, CSTNC members burnt tyres and blocked traffic in the Noumea area to win the reinstatement of two workers sacked by the SLN nickel company.
Two weeks ago, employers held unprecedented demonstrations to urge the French authorities to maintain freedom of movement.
Mr Nea is to be heard again in April as police continue their investigations.