BEIJING - Chinese alcohol producer Jiugui Liquor Co on Thursday apologized to consumers and investors after quality supervisor found excessive levels of a toxic chemical in a sample of its product.

The Hunan-based company vowed to scrutinize every link in its transportation and packaging processes, determine the cause of the contamination and make rectifications, it said in a statement to the Shenzhen Stock Exchange.

The company's share will resume trading from Friday after a four-day suspension, the statement said.

The General Administration of Quality Supervision, Inspection and Quarantine said Wednesday that tests conducted by its Hunan branch found that liquor samples from Jiugui contained 1.04 mg of dibutyl phthalate (DBP) per kg, a kind of plasticizer.