Around 20 companies affiliated with English-language school operator GEOS Corp. failed to declare some 280 million yen in income in the five years to March 2000, industry sources said Thursday.

This total includes 130 million yen in concealed revenues, the sources said.

Auditors at the Tokyo Regional Taxation Bureau who investigated the Tokyo-based company also found that GEOS President Tsuneo Kusunoki and his wife, who serves as vice president, failed to report more than 200 million yen in personal income in the three years through 1999, they said.