The Tokyo Regional Taxation Bureau has found that NTV Corp. failed to declare about ¥150 million in taxable income for a two-year period through March 2012, sources said Friday.

The bureau categorized ¥74 million used for entertainment among employees as concealed income, the sources said, while the company formally known as Nippon Television Network reported the amount as tax-exempt expenses.

The authority levied ¥87 million in back taxes, including a heavy additional tax, and NTV is believed to have revised its tax return, the sources said.