The leader of Fiji's Labour Party, Mahendra Chaudhry, says his country is a dictatorship.
The former prime minister was one of six prominent figures arrested and detained overnight at the weekend after speaking at a public seminar about the Fijian constitution.
The police said the meeting breached a public order decree.
Mr Chaudhry said he was treated fairly but his experience was a nightmare.
"As far as we are concerned you don't require a permit for forums of that nature where it is not a political meeting," he said.
"The Prime Minister was invited to this and also the Attorney-General was invited to this. They didn't come, they declined to come. We want to live in a free society, not where there are restrictions on free speech."
Fiji Labour Party leader Mahendra Chaudhry taken away from the Totogo police station in Suva. pic.twitter.com/z90psL8cW9— Alex Perrottet (@alexperro) September 11, 2016
National Federation Party (NFP) leader Biman Prasad, Sitiveni Rabuka - the leader of largest opposition party Sodelpa, Fiji Council of Trade Unions general secretary Attar Singh, academic and former politician Tupeni Baba, and Jone Dakavula from the organisation Pacific Dialogue were also detained by the police.