TOKYO - A former aide to Japan's Prime Minister Yukio Hatoyama is facing indictment for misreporting political donations, media reports said Tuesday, in a worsening headache for the new leader.

Prosecutors are also investigating whether Hatoyama was involved in the book-keeping irregularities, Jiji Press reported, while the Asahi Shimbun daily said prosecutors had so far found no evidence against him.

The former secretary, who has not been named, is likely to be indicted on charges of violating the political funds control law although he is unlikely to be arrested, media report said without citing sources.

Tokyo prosecutors, who routinely telegraph their actions through media leaks, are looking into charges that the aide misreported more than 200 million yen (2.27 million dollars) in political donations, the reports said.

Hatoyama fired the aide in June, when he was still opposition leader, and admitted to sloppy account-keeping by the fund-raising body, which had listed dead people as well as people who later denied giving money.

The centre-left prime minister hails from a wealthy political family often dubbed "Japan's Kennedys" and has also faced accusations he used his personal wealth to bankroll some of his political activities.

The former secretary is likely to be indicted after the current parliament session ends this month or in December, the reports said.

Hatoyama, who took power in mid-September after a landslide election victory, has so far declined to comment on the accusations in detail, citing the ongoing investigation.