Japan’s health ministry has asked importers of Chinese beers, which are increasingly popular here, to confirm the drinks are safe after reports they contain a cancer-causing agent, officials said. “We have told quarantine offices to ask the importers to check the ingredients” with all manufacturers of Chinese beer, a health ministry official said.Japan’s 31 food quarantine offices will make the move after a report last week in the South Korean newspaper Joong-Ang Ilbo that Chinese beers contain a large amount of formaldehyde, a potentially cancer-causing chemical which Japan bans in food.THe Japanese official said the probe depends on the good faith of Chinese beer makers as there is no established method to detect formaldehyde in beer, unlike in water, fish and some other food.Brewers usually use silica gel, which is not hazardous, to remove unwanted substances from beer but some Chinese brewers may be using cheaper formaldehyde to cut costs, Kyodo News agency quoted Japanese government sources as saying.Japan and China have seen trade grow rapidly in recent years despite frequent political friction over Japan’s imperial history and disputed energy resources.