Around 66,000 companies in Japan failed to report a total of ¥751.5 billion in taxable income during the 12 months through June 2014, according to the National Tax Agency.

The amount was down 24.8 percent from the previous year., the agency said Thursday. Of the 66,000 companies, 17,000 were found to have deliberately concealed taxable income totaling ¥218.4 billion, down 20.8 percent from a year earlier.

The number of companies investigated by tax authorities declined 2.8 percent from a year earlier to 91,000, a record low since comparable data became available in the year to June 1968.

The decline was attributed to a legal revision in January last year that increased the workload on tax investigators and required more time to probe each case, according to the agency.