An advertisment displaying L&M cigarettes, which is the brand of Philip Morris, at a kiosk along a road in Karachi, Pakistan April 6, 2018. REUTERS/Akhtar Soomro

SEOUL (Reuters) - Philip Morris Korea Inc. said on Monday it has filed a lawsuit against the South Korean government, demanding the disclosure of information on a recent test that concluded electronic cigarettes contain harmful substances.

Seoul's Ministry of Food and Drug Safety said in June after a study that up to five cancer-causing substances were found in the heated smoking devices, and the level of tar discovered in two products, including Philip Morris' PM.N iQOS, exceeded that of regular cigarettes.

The ministry’s announcement ran counter to the U.S.-headquartered company’s claim that its electronic gadget is less likely to cause disease than traditional cigarettes, citing studies conducted in Germany, Japan and China.

Philip Morris said it raised a suit with the Seoul Administrative Court after the ministry declined the firm's request for the disclosure of data used in the test, which also involved British American Tobacco's BATS.L Glo, and South Korea-based KT&G Corp.'s 033780.KS lil.

A ministry representative said that the agency “will follow legal procedures as required.”

The company said the government study wrongly centered on tar, which is only applicable to smoke created by regular cigarettes, while the electronic devices do not generate smoke.

“Due to the focus on tar, the ministry’s study resulted in encouraging customers to stick to conventional cigarettes instead of choosing products that contain sharply lower levels of harmful compounds,” Brian Kim, corporate affairs director of the tobacco maker, said in a statement.

The smoking gadgets have seen a spike in popularity since they launched in South Korea last year.

Sales of the devices hit a record of 30.4 million units last May, with their collective stake reaching 10 percent for the first time, but have fallen to around 9 percent until August due to the drug agency’s study, according to Seoul’s finance ministry.