Self-employed business operators and doctors failed to declare a record 1.405 trillion yen in the 12 months to June 30, the National Tax Administration said Friday.

The figure topped the previous high of 1.395 trillion yen registered in the 12-month period up to June 1998, and represented a slight increase from the 1.383 trillion yen registered a year earlier.

The tax agency said its survey of 748,000 people, including company employees who earned money through land transactions, shows that some 613,000, or 82 percent, failed to declare their incomes properly.

The agency slapped the tax evaders with 28.8 billion yen in back taxes and penalties, saying the number of those failing to declare income accidently rather than deliberately is rising.

Moneylenders formed the worst group of income tax evaders, with an average 38.84 million yen in undeclared income, compared with 1.88 million yen on average -- up 160,000 yen from a year earlier -- for all tax evaders, the agency said.

Sex establishment operators ranked second with 26.01 million yen, followed by hospital owners with 17.86 million yen, the agency said.

Although pachinko parlor operators remained the worst offenders with 39.98 million yen on average in undeclared income, they were dropped from the self-employed statistics because many such operators had turned their operations into companies, the agency said.

As for overseas transactions, one former businessman was cited for failing to declare 30 million yen in income from overseas pornographic ads on his Web site.

One executive failed to declare income by depositing his remuneration as an executive of overseas subsidiaries in bank accounts in Britain and Hong Kong.