Executives of a Tokyo-based company that sells health food products and promises to help clients set up their own health food business have gone into hiding, taking with them several billion yen of company funds, according to sources close to the case.

The sources said the company, I.A.S. Produce, revealed the situation in a letter to clients and members in late April.

The exact mount of funds that have disappeared, apparently revenues collected from the company's clients and members, is not known. The letter spoke of "several billion yen" in cash and securities.

The sources said I.A.S. members -- those who have bought at least 300,000 yen worth of products from the company -- have been unable to contact the I.A.S. president or other senior executives.

In the letter, sent under the name of the firm's 53-year-old president, the company said the losses have been reported to police. The company's senior managing director and sales manager were listed among the people who have allegedly absconded with the money. None of the executives were identified.

According to former employees and other sources, I.A.S. was set up in October 1999 with 30 million yen in capital. Its head office is in Minato Ward.

The company operates by offering members an opportunity to sell health food products, including Brazilian tea and propolis, as well as setting up businesses.

A person who buys 300,000 yen worth of health food products from the company is ranked as an I.A.S. agent.

A 1.5 million yen purchase is rewarded with a general agent rank. When the purchases top 7.5 million yen, the client is recognized as a sales company.