A Chinese company reportedly substituted glycerine, a safe liquid having medicinal uses, with diethylene glycol in the production of cough syrup.

Diethylene glycol is an industrial solvent and ingredient in petrol and diesel engines.

There have been no cases detected in Singapore of diethylene glycol being used in cough syrup instead of glycerin, the HSA said.

Manufacturers are being advised to exercise "additional caution" when purchasing raw materials, the spokesman said.

In 2002, Slim 10 pills, a China-made product that contained the banned substance fenfluramine, caused the death of one woman in Singapore and forced another to undergo a liver transplant.