KOTA KINABALU (THE STAR/ASIA NEWS NETWORK) - Thousands of fish ended up dead in a monsoon drain in the industrial area of Kolombong in the Sabah capital of Kota Kinabalu, raising concerns about the possibility of toxic chemicals being discharged into drains.

The Department of Environment (DOE) has been ordered to conduct an immediate investigation into cause of the death of the freshwater fish, mostly tilapia.

State Tourism, Culture and Environment Minister Datuk Masidi Manjun said the DOE should check the water quality and industrial waste in the Kolombong area.

Cases of fish found dead have occurred in the past.

However, the cause of those deaths remained a mystery despite investigations by the state Fisheries Department and other agencies.

The latest incident happened late Saturday at a monsoon drain that connects to Sungai Likas where a large number of dead fish was found among the filth and garbage.

DOE officers took samples of the fish and water for analysis on Sunday.