Prosecutors plan to indict on Tuesday the secretary of Democratic Party of Japan President Ichiro Ozawa over the fundraising scandal that has deviled the opposition party since early this month, according to sources.

Ozawa is expected to announce, possibly also Tuesday, whether he will resign from his post. Some in his party have expressed support, saying he doesn't need to step down even if Takanori Okubo, 47, is indicted.

Okubo was arrested March 3 on suspicion of taking illegal donations from Nishimatsu Construction Co. and falsely reporting them as donations from dummy entities in violation of the political funds control law. Corporations are banned from making contributions to individual politicians.

Ozawa apparently intends to decide his own fate based on how Okubo's case is handled by investigators and how the issue could affect the DPJ's prospects in the next House of Representatives election, which must be held by the fall because the current term for Lower House members expires in September.

The special investigation squad of the Tokyo District Public Prosecutor's Office has apparently gained approval from the Justice Ministry and other authorities, the sources said.