The shrine authorities said some big fish died Thursday noon in a sign of poisoning and all species floated dead in the pond waters by yesterday evening.

Hazrat Shahjalal had raised the fish in the pond. After death of the Muslim saint, the fish have been reserved for long.

A bottle of poison was found in the pond after a hectic search followed the death of the fish.

Azizul Haque Manik, ward commissioner of Sylhet City Corporation, told the news agency: "The fish died from poison."

Mufti Nehal Uddin of the shrine described the death of fish as an act of sabotage.