Foreign Minister Murray McCully says New Zealand is keeping a "close interest" in recent reports of arrests of Opposition MPs in Fiji.
Fiji media have reported the leaders of two opposition parties and a trade union official were detained by Fiji authorities after taking part in a forum on Fiji's Constitution.
Those in custody included the leader of Sodelpa Sitiveni Rabuka, leader of the National Federation Party Biman Prasad, and trade unionist Attar Singh.
A spokeswoman for Fiji Police told the Fiji Times several people were being questioned for comments at the forum which "could affect the safety and security of all Fijians."
Speaking in the Federated States of Micronesia, McCully said he had asked Fiji's representative at the Pacific Islands Forum, Ratu Inoke Kubuabola, to convey New Zealand's "close interest" in the developments.