Questions have deepened over fund-reporting irregularities involving ruling party kingpin Ichiro Ozawa, with the amount of unrecorded cash transfers believed to be twice as much as initially thought.

Sources said Ozawa's fund management group, Rikuzankai, transferred ¥400 million to Ozawa in 2007 without recording the transaction in a fund report. Rikuzankai is also suspected of using ¥400 million in unrecorded income to buy land in Tokyo in 2004.

Democratic Party of Japan Lower House lawmaker Tomohiro Ishikawa, who was a secretary at Rikuzankai at the time of the land purchase, has owned up to the irregularities in connection with the purchase of a 476-sq.-meter land plot in Setagaya Ward for about ¥340 million.

Ozawa has said the land was purchased with ¥400 million borrowed from a financial institution in his name. But other sources have said the land was paid for before the loan was extended, raising suspicions that Ozawa used his own money to buy the land.

Prosecutors have received a criminal complaint against Ishikawa and two others.