The health ministry has asked importers of Chinese beers to find out from the breweries whether the drinks contain formaldehyde, a banned hazardous substance, according to ministry sources.

The Health, Labor and Welfare Ministry also asked the Chinese government via the Foreign Ministry in Tokyo to probe allegations that some imported Chinese beers contain formaldehyde, the sources said Monday.

The health ministry decided to launch the probe as it had received information that some Chinese beers may contain a large amount of the chemical, which is banned in Japan under the Food Sanitation Law, the sources said.

Brewers usually use silica gel, which is not hazardous, to remove some substances from beer to keep it stable, but some Chinese brewers may be using formaldehyde to cut manufacturing costs, the sources alleged.

China breweries run in partnerships with foreign firms are reportedly not using formaldehyde, they said.

According to the Finance Ministry, imports of Chinese beers rose to about 1.78 million liters in 2004 from about 690,000 liters in 2000.