China has banned 10 domestically made cosmetics that contain a substance that could cause the skin to become discolored and susceptible to disease.

The state-run Xinhua news agency says the lotions and masks are produced by two companies in south China's Guangdong province.

Xinhua says the cosmetics contain dexamethasone or "skin opium" that initially makes the skin seem improved, but over time makes it thin and dark.

Dexamethasone is a powerful steroid that has several uses in human medicine and can be used to treat ear infections in dogs.

The news agency did not report whether a recall has been issued for the products or if any of the products have been exported.

In recent months there have been a series of disclosures involving unsafe or substandard China-made products ranging from pet food to toys.

Some information for this report was provided by AFP and Reuters.