SAMPLES of the poisoned fish pond in Maqalevu in Nadi have been taken for testing by the police.
Nadi Police Station officer in charge ASP Simione Bale said they were investigating the incident in which 8000 tilapia died.
ASP Bale said it was too early to say what caused the mass death of fish.
"We are investigating the case and a sample of the water has been taken for testing," he said.
He said foul play could not be ruled out.
"We will determine all of that once we get back the results of the samples," ASP Bale said.
The fish farm has five ponds in which the 8000 were bred.
Farm owner Peniasi Siga said the fish had been ready for harvest and that the loss cost him $13,000.