Police plan to provide information to the Tokyo Regional Taxation Bureau on a publishing house connected to the chairman of a rightwing group for not declaring more than 300 million yen in book sales to the Defense Agency, state-run universities and other clients, police sources said Tuesday.

According to police investigations, the Tokyo-based publisher, effectively owned by Takeshi Otsuki, earned about 337 million yen in the last 18 months by selling a book on minority discrimination issues for 60,000 yen each, the sources said.

Otsuki, 46, heads the Aikyosha rightwing group. He has been indicted on a charge of violating a weapons control law.

Police plan to provide information to taxation authorities about Otsuki and the publisher on suspicion the company failed to declare its income, the sources said.

Otsuki allegedly received nearly 40 percent of the sales worth about 76 million yen from the publisher last year, and police suspect the money was used for the rightwing group's activities, the sources said.

Otsuki was arrested last month for possessing a gun and Japanese swords. He was indicted earlier this month.

According to police investigations, the publisher was established in 1997 and its president is an acquaintance of Otsuki.

Company staff phoned ministries and agencies, universities and companies to sell the book, and sent the books to them with a payment remittance slip, the sources said.

The Defense Agency's press office confirmed that the agency's library purchased a copy of the book, but it is still investigating details of the purchase.