Police in Fiji have charged three people with an alleged plot to assassinate the country's military leader, Frank Bainimarama.
Fiji saw its most recent coup less than a year ago
A total of 16 people have been arrested in connection with the claims, including businessmen and politicians.
New Zealand Prime Minister Helen Clark said one of those arrested, a New Zealander, had been badly beaten.
Commodore Bainimarama came to power after a bloodless coup in late 2006, but has pledged to hold polls in 2009.
Fiji has seen four coups in the past two decades.
No concrete details have been given about the alleged plot, but Cmdr Bainimarama blamed it on "disgruntled groups" affected by his anti-corruption drive.
"Such people have the potential to go to extremes in undermining the work which the interim government has been mandated to undertake," he said in a statement.
Police chief Esala Teleni declined to name the three people who have been charged, but said the alleged offences included treason, inciting mutiny and conspiracy to murder.
He said the police were satisfied they had "successfully blocked any threat to the government, the community and the safety and wellbeing of tourists in this country".
A New Zealand businessman, Ballu Khan, who is based in the Fijian capital, Suva, was among those arrested.
Mr Teleni told journalists that Mr Khan suffered "minor injuries" when he resisted arrest, but other reports suggest he was so badly beaten that he was unable to talk.
A hospital source quoted by Reuters news agency said he had a broken jaw and ribs.
New Zealand Prime Minister Helen Clark said the way Mr Khan had been dealt with was "disgraceful".
"They held this man back from proper healthcare in a hospital for far too long and they beat him when he was in custody."
Both New Zealand and Australia have dismissed Fiji's suggestion they were involved in some way with the alleged coup plot.
Australian Foreign Minister Alexander Downer told reporters the allegations were "completely absurd", while Mrs Clark described the claims as "wild statements".