Livedoor Holdings concealed about 920 million yen in income it made from a business deal which was later determined in court to be an attempt to pad its accounts, The Yomiuri Shimbun learned Thursday.

The Tokyo Regional Taxation Bureau also did not recognize the company's corporate acquisitions expenditures as necessary expenses, sources said.

The new revelation brings Livedoor's total undeclared income to 2.36 billion yen in four years through September 2006.

Back taxes, including penalties, imposed on Livedoor Holdings--formerly Livedoor Co.--are believed to total about 870 million yen. The company has already revised its income declaration for the year ending September 2004 and paid 1 billion yen in back national and local taxes.

According to company and court records, the company falsely booked a total of 1.58 billion yen--deposits from online service operator Cueznet Co., another firm that it was planning to acquire and funds from other sources--as sales in the business year ending in September 2004.

Tax authorities concluded that 920 million yen that was paid to Livedoor by Cueznet as payments for fictitious transactions should be regarded as a donation from Cueznet to Livedoor. The company eventually acquired Cueznet.

Authorities did not approve Livedoor's booking of about 1 billion yen as expenses to amortize goodwill of five companies with which Livedoor merged or integrated operations in 2001 and 2002.