Investigators are looking into how clothing containing cancer-causing agents found its way onto shelves at Wal-Mart, Carrefour and several local leading chain stores, according to a report posted yesterday on the website of the Beijing Administration For Industry and Commerce (BAIC).

Certain apparel made by 28 clothing brands sold in these stores failed quality inspections earlier this month because they contained unsafe materials, the administration found.

The BAIC ordered the substandard apparel off all shelves in all stores in Beijing. Both the sellers and producers of the clothing may face prosecution, while the producers have been ordered out of the Beijing market.

Of the 28 brands listed, certain apparel made by four companies was found to contain excessive levels of chemicals like aromatic ammine or formaldehyde, which are both carcinogenic substances.

Many countries have banned the use of the former as a dye, while the latter is generally not allowed in consumer products.

Apparel from the four unsafe brands were: Ming-Langdike skirts (size 11), made by the Guangzhou Disheng company; Pusheng blouses (155/80A), made by Shanghai Pusheng; Jeanberger trousers (170/80A), made by Shenzhen Zhonghang; and Hafulu trousers (size 23), made by the Guangdong Hafulu.

The BAIC inspectors also found that apparel made by four brands exceeded the allowable pH values for clothing. The use of materials with excessive acidity or alkalinity could irritate people's skin.

The other brands on the list either failed to correctly list the materials used in the production of their apparel or were found to change shape and colour after washing.

The full list of substandard items has been published on the BAIC's website, www.hd315.gov.cn.

BAIC officials said there would be penalties for the involved parties.

"They could face fines worth up to three times the revenue they got from selling the goods and will be forced to exit the market," Wang Xiaojing, of the administration's information department, told China Daily.

"Buyers may return substandard goods if they have kept the receipt. They should first make sure their purchases are included on the list published on our website," Wang added.

In addition to Wal-Mart and Carrefour, substandard clothing was found on shelves at nine other chains, including Lotus Liuliqiao, Wangfujing Women's Collection and a Beijing Hualian Group branch.

An official at Wal-Mart said the retailer no longer carried the offending brands.

"The problematic trousers are no longer sold in our stores," a Wal-Mart representative told Xinhua, adding that he was unaware of the investigation.

This is at least the second report of unsafe clothes being sold in the capital city's leading chain stores to appear in the second half of this year.

Earlier in September, Beijing's municipal government suspended the sale of 79 children's products deemed substandard by officials. The products included clothing, stationery, eyeglasses, shoes, toothbrushes and toys.