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.

"Obviously anything that constrains free speech and space for legitimate political debate would be a concern to the New Zealand Government. I've simply conveyed that to Ratu Inoke and asked him to convey to his Government our close interest in how this plays out."

McCully said he understood several people were taken into custody because there was no permit to hold that forum. Fiji's law requires permits for public gatherings - a requirement criticised as an attempt to stifle freedom of speech.

McCully said New Zealand was trying to support Fiji democracy and was pleased with its 2014 elections but some of its laws were "from a past era."

"How they are dealt with by the authorities is of close interest to us. We don't live in a perfect world and we want to try and keep on encouraging those who are moving things in a good direction. But we don't shirk our responsibility to take interest where matters suggested we should."

Labour leader Andrew Little said it was concerning.

"At a time Fiji is trying to convince the world it is a normal democracy, we now have what looks on the face of it like a clampdown on those either criticising or challenging the Constitution. That ought to be allowed in a democracy."

The arrests coincided with a Cabinet reshuffle by Fiji's Prime Minister Frank Bainimarama in which Bainimarama appointed himself Foreign Affairs Minister and moved the former Foreign Minister Ratu Inoke to Minister of Defence.

That took place while Ratu Inoke was at the Pacific Islands Forum in the Federated States of Micronesia with McCully and Prime Minister John Key as well as other Pacific leaders.

The change will concern New Zealand. Relations with Bainimarama remain tense but Ratu Inoke was instrumental in maintaining a constructive relationship with New Zealand during the years of the coup when most high-level contact was suspended.

Bainimarama has boycotted the Pacific Islands Forum in protest at the involvement of New Zealand and Australia, despite Fiji being reinstated as a full member after holding elections in 2014.

Key's visit to Fiji earlier this year did little to change Bainimara's mind - instead Key was treated to a diatribe about New Zealand's sanctions of Fiji during the coup years and involvement in the region.

Key said he hoped Bainimarama would eventually join the leaders' forums but New Zealand would not meet his wish to withdraw from the Forum.