Authorities are yet to determine how a 150-kilogram catfish, discovered in the Mekong River on Monday, died.

Hor Veng Nai, from Kbal Koh district, said villagers stumbled on the fish about 7am yesterday in Phnom Penh’s Meanchey district and dragged it to shore where they measured it at 2.3 metres and alerted authorities.

“The other villagers flocked to see the fish,” he said.

“They’d never seen it before and pitied it,” he said.

“Authorities examined the fish to check it did not die from fishing nets set by fishermen, but there was no cause [of death] yet and it was sent to the Tonle Sap lake authority for examination by an expert official.”

It was likely the fish had recently died because it did not stink, Hor Veng Nai said.

Alan Brooks, regional director of the World Fish Centre, said although catfish numbers were declining due to unregulated fishing, depletion of species down the food chain and dam development, it was not particularly unusual to find a 150-kilogram specimen.

“We get one or two every couple of years,” he said.

“This would be regarded a medium-sized catfish. The largest caught was . . . about 300 kilos, seven years ago.’’

Noa Thouk, head of the Fisheries Administration, could not be reached for comment.

WITH ADDITIONAL REPORTING BY DAVID BOYLE