ALOR STAR: Farmer Mat Rejab Said had been hoping to make RM10,000 (S$4080) in duit raya from selling his red and black tilapia.

However, his hopes were dashed when he found about 20,000 of the freshwater fish belly-up in his aquaculture farm in Kampung Tanah Lot Pondok Haji Majid, Guar Chempedak, near here on Wednesday.

"It is all gone now. I don't know what happened.

"For the past few weeks, the fish had been healthy."

The 69-year-old, who operates the aquaculture farm jointly with a friend, suspects that the irrigation canal, which houses his 46 fish cages, had been contaminated.

"I don't know the source of the contamination or poisoning or if it started from upstream.

"One thing for sure is that the colour of the water in the canal is different."

An officer from the State Fisheries Department visited the canal to collect samples of the water and dead fish for analysis.