Newly appointed Democratic Party of Japan Secretary General Katsuya Okada on Wednesday urged former party leader Ichiro Ozawa to give a full and public account of how money allegedly illicitly donated by Nishimatsu Construction Co. was used.

Ozawa abruptly stepped down last week amid a political funds scandal involving Rikuzankai, his political funds management body, which allegedly received ¥21 million from Nishimatsu between 2003 and 2006. Ozawa's chief secretary and accountant of the group, Takanori Okubo, was arrested and charged in March for violating the Political Funds Control Law.

"What the people are questioning most of all is what the money was used for," Okada said at the Japan National Press Club in Chiyoda Ward, Tokyo. "Since Ozawa stepped down as president, the situation may have changed, but if the public still has doubts, I would advise Ozawa" to clarify the expenditure.

However, he went on to say it is "unreasonable" to force Ozawa, who has denied involvement in managing the funds, to discuss the Nishimatsu scandal ahead of Okubo's trial.

"The Nishimatsu incident is undoubtedly going to be discussed at trial and I think it's unreasonable to ask Ozawa to offer an explanation to the public at this moment," Okada said. "As long as Ozawa says he didn't know anything about it, there's nothing further to explain."

By law, corporations are banned from donating to individual lawmakers, although they can contribute to political parties and their branches.