One of Japan's largest phone dating service operators and its five affiliated companies have been charged with hiding 1.2 billion yen in taxable income over a three-year period through March 2003, sources familiar with the case said Wednesday.

The Tokyo Regional Taxation Bureau filed charges with prosecutors against My Media, the phone dating service operator based in Shibuya Ward, Tokyo, and its five affiliates, suspecting they evaded a total of about 350 million yen in taxes by hiding the income, the sources said.

My Media President Yoshinori Hiraiwa, the company's former president, Daisuke Koibuchi, and executive Yasuhiko Nishino, a certified tax accountant, have also been accused of being involved in the case.

My Media and its affiliates provide customers with a phone message service and a direct link service.

The companies hid the income by declaring only part of their revenues and by booking fictitious retirement allowances for executives, the sources said.

The hidden income has been deposited at banks or loaned to acquaintances of Hiraiwa and the two others, they said.