OSAKA — The Osaka District Public Prosecutor’s Office on Tuesday demanded an 18-month prison term for former Osaka Gov. “Knock” Yokoyama, who was accused of molesting a 22-year-old female campaign worker during his re-election drive in April last year.

At the trial’s sixth hearing before the Osaka District Court, prosecutors said the actions of the former governor were “a disgrace and previously unheard of.” They added that Yokoyama’s harassment was premeditated and persistent.

According to prosecutors, Yokoyama, 68, groped the woman for about 30 minutes in the back seat of a campaign van on April 8, 1999.

“While there is a wide range of acts defined as obscene, (Yokoyama’s) can be called a grave violation of human rights,” the prosecutors said, adding that the defendant shows no sign of changing his attitude and that the case shocked Osaka citizens and threw prefectural politics into turmoil.

Yokoyama pleaded guilty at the first hearing of his criminal trial, which forced him to step down in December, but has maintained that the act was not planned. He also denied the woman’s claim that he forced her legs apart and groped her continuously for 30 minutes.

Yokoyama said that while he did grope her, the woman barely resisted and the act lasted for about 10 minutes.

A lawyer for the plaintiff said the same day that the prosecutors’ demand was natural and anticipated, and that the woman is hoping Yokoyama is sentenced to prison.

The court is expected to hand down a ruling as early as July.

When media reports on the allegations initially surfaced last year, the comedian-turned-politician denied the accusations.

Even after the first hearing of a 15 million yen damages suit the woman filed against him in October, Yokoyama called the woman a liar and refused to contest the civil case.

However, public criticism over his actions eventually forced him to resign.

The district court ordered Yokoyama to pay 11 million yen in damages to the woman in December.