Relatives of people who died after taking the lung cancer drug Iressa filed criminal complaints Friday against the Japanese distributor and its former president, alleging the medicine was advertised for use before it was approved.

In the complaints filed with the Tokyo and Osaka District Public Prosecutor's Offices, the relatives said AstraZeneca K.K.'s Web site advertisements, pamphlets and information publications for doctors between October 2001 and June 2002 stated the drug "will not lead to any serious side effects" and was "a dream-like medicine," without mentioning the potentially fatal side effects.

The relatives alleged the Japanese subsidiary of the British pharmaceutical company AstraZeneca PLC violated the Pharmaceutical Affairs Law, which bans misleading advertising and the advertising of unauthorized drugs.

Osaka-based AstraZeneca said it had not yet examined the details of the complaints but that "there has been no infringement of the Pharmaceutical Affairs Law as reported in the media, and we, firmly believe our company as well as the former president and others bear no criminal liability."

Iressa, the trade name for gefitinib, was approved by the government in July 2002.

It is a highly effective cancer treatment drug for some patients. But about 600 patients in Japan have died from illnesses, including interstitial pneumonia, suspected to be side effects of the drug.

A study group in the Health, Labor and Welfare Ministry concluded in January that it saw no need to limit the use of the cancer-fighting drug.

"I was aware of the contents of the information publications in early 2002, and thought that an extraordinary drug had emerged," said one of the deceased patient's relatives, Akio Chikazawa, 60, from Saitama. "We should not have a repeat of a similar incident (of releasing a misleading ad) for a cancer drug in the future."