OSAKA -- A 21-year woman filed a 12 million yen damages suit Tuesday against Osaka Gov. "Knock" Yokoyama, accusing him of sexually harassing her while she was working for his re-election campaign in April.

According to the suit filed with the Osaka District Court, Yokoyama groped the woman for over 30 minutes in the back seat of a campaign van on the afternoon of April 8, three days before election day.

On April 9, the woman filed a complaint with the Osaka District Public Prosecutor's Office. Yokoyama was re-elected two days later with more than 2.35 million votes, an unprecedented number for any Osaka governor.

Yokoyama has denied the accusation since initial media reports broke, and filed a complaint of his own against the woman on April 15 at the same office, arguing he was falsely accused.

The suit filed Tuesday claims that Yokoyama's complaint constituted libel. The complaints are still under examination by the prosecutor's office.

For the damages suit, 81 lawyers across the country have joined forces to support the woman.

Chief lawyer Noriko Ishida said that abuse of a weak woman by a powerful man could not be overlooked. The responsibility of the governor, who is supposed to protect the rights of sexually abused women and prevent crimes against them, must be questioned, she said.

Yokoyama commented Tuesday that he could not say anything since he had not read the suit, but hopes the truth will come out as soon as possible.