The acquittal of influential lawmaker Ichiro Ozawa for misreporting political money was finalized Monday, with prosecutors saying they have given up the right to appeal the ruling.

The move came as Ozawa, a former president of the ruling Democratic Party of Japan, is gearing up for a general election next month as head of the political party he formed after leaving the DPJ earlier this year.

"It took three years and seven months since the start of the prosecution's investigation to the end of the trial. Each day was about patience, and this was a very difficult time," said Ozawa at a news conference in the evening.

"I have said from the start that I had done nothing wrong, and (the acquittal) was proof of what I've stated," he said. "But without the support of many people, I would not have been able to live through this pressure."

The court-appointed lawyers serving as prosecutors under a special criminal trial system made the decision before the Nov. 26 deadline for appealing the not guilty ruling by the Tokyo High Court.

Shunzo Omuro, one of the lawyers acting as a special prosecutor, said they "could not see the reasons for appealing the ruling."

"It would not be right to prolong the period for keeping Ozawa a defendant," Omuro said.

The court cleared the 70-year-old Ozawa of conspiring with former aides to falsify figures in a 2004 report by his political fund management body, Rikuzankai, citing a lack of evidence.

The court also reaffirmed the Tokyo District Court's judgment that Ozawa, who now heads Seikatsu ga Daiichi (People's Life First), was not aware of the illegality.

The three former aides were convicted and are appealing their sentences.

Ozawa was sent to trial by an independent citizens' panel after the regular prosecutors decided against indictment.