One of Japan's best-known politicians has resigned as governor of Osaka amid allegations that he sexually harassed a university student.

Knock Yokoyama, 67, who is currently in hospital with a heart condition, stepped down citing "personal reasons".

Pressure has mounted on Mr Yokoyama to resign since a court last week ordered him to pay Y11m ($106,630) in a ruling on a civil damages suit filed against him by the student.

This was the largest ever pay-out in a sexual harassment case in Japan.

Mr Yokoyama's resignation came after prosecutors raided his office and his residence, following the decision by the unnamed 21-year-old woman to file criminal charges.

The governor, a former stand-up comic who is also known as Isamu Yamada, has repeatedly denied the allegations, but he did not appear in court to contest them.

Focusing attention

His decision removes a month-long political cloud over Japan's second-largest administrative region with a population of more than 8.6 million people. The area includes the major industrial city of Osaka.

Mr Yokoyama was censured by a prefectual assembly, but this was largely symbolic and did not prevent him from carrying out his duties.

His alleged victim had worked as a campaign assistant for the governor. She accused Mr Yokayama, who was re-elected as govenor in April, of fondling her in his campaign van.

The case has focused attention of the issue of sexual harassment in Japan, which correspondents say is common but has only recently been acknowledged as a problem.

Several women's groups have held rallies in Osaka to demand the governor's resignation.

An election to replace him must be held within 50 days.