British drugmaker GlaxoSmithKline Plc (GSK) could face prosecution after a children’s antibiotic on sale in Hong Kong, was found to be tainted with a plastics chemical, health officials said Friday.

The city’s Health Department ordered the recall of the French-made powder version of Augmentin on Thursday, after tests found it contained two times the permitted European limit of a chemical called Diisodecyl phthalate.

The substance belongs to a group of chemicals known as plasticizers, which are used to make hard substances more malleable.

A department spokesman said it was possible the drug company had contravened health and safety laws in allowing the tainted product to be distributed and the case had been referred to the Department of Justice.

Hong Kong has stepped up its surveillance of certain products containing flavouring agents after a recent scandal in Taiwan in which similar, but more toxic plasticizers were found in products that included sports drinks and teas.

Augmentin is an antibiotic used to treat bacterial infections and is usually issued to children in the form of syrup made from flavoured powder.

The spokesman said that although Diisodecyl phthalate’s safety in humans was not established, tests on animals had found long-term consumption could affect the liver.

“It is a fact that the department has not received any report of adverse events related to the product, but GSK has failed to demonstrate the safety of the tainted product to our satisfaction,” he said. “The threat to public health cannot be ruled out as this stage.” Parents of children taking the drug have been advised to consult their doctors as soon as possible but not to stop using it abruptly; otherwise it could lead to the development of antibiotic-resistant bacteria.

A GlaxoSmithKline spokesman said the company was seeking professional advice on the recall. It said the chemical had not been added intentionally and it belonged to a group of plasticisers that are present in trace compounds in the environment and in many items that are consumed daily.