TOKYO - JAPAN'S opposition leader Ichiro Ozawa said on Tuesday he would decide his future when prosecutors announced if a senior aide would be indicted in a fundraising scandal, a ruling expected within a week.

The scandal, in which the aide was arrested this month on suspicion of accepting illegal corporate donations, threatens support for Mr Ozawa's Democratic Party ahead of this year's general election, which the party had looked likely to win.

'I think that the prosecutors will make a decision not so far away from now,' Mr Ozawa told a news conference. 'When they reach a decision, I would like to make a decision.'

The 66-year-old Democrats leader reiterated at the news conference that he has not been involved in corrupt practices and said that he has not heard from the prosecutors.

Media polls show most voters want Mr Ozawa to quit but the scandal has done little to boost support for Prime Minister Taro Aso's ruling Liberal Democratic Party as some of its lawmakers said they had also received donations from a construction firm at the heart of the affair.

Prior to the scandal, a political stalemate and voters' frustration with Mr Aso had raised the chances Mr Ozawa would lead to his party to victory in this year's lower house election, which would end more than 50 years of nearly unbroken rule by the LDP.

Generally speaking, prosecutors have around three weeks to decide whether to charge an arrested person, an official at the Tokyo District Public Prosecutor's Office said.

He declined to comment on specific cases, but next Tuesday it will be three weeks since Mr Ozawa's aide was arrested. -- REUTERS