Japan's top police chief has resigned following a spate of scandals, including allegations of drug abuse and sexual harassment, which have dented the force's image.

National Police Agency chief Yuko Sekiguchi, 60, said that now a clean-up of the force was nearly finished it was the right time to step down.

However, he said his resignation did not imply that he was taking responsibility for any wrongdoing.

Cover-up

The force's generally clean image was shattered last year by allegations that senior officials in a Tokyo suburb covered up drug abuse by a colleague.

The prefecture police chief and several other officials have been arrested.

Other scandals inside the 260,000-strong force have involved allegations of extorting money from suspects, sexual harassment and bullying.

There was even one case of hit and run, where a police car ran a member of the public over and left the scene of the crime.

Scandal

Mr Sekiguchi said his recent plan to bolster the National Public Safety Commission, the body which supervises the nation's police force, had been completed.

His resignation is expected to be approved by the cabinet this week and he is likely to be replaced by the agency's deputy chief, Setsuo Tanaka, 56.

Prime Minister Keizo Obuchi said last year that the crimes were "beyond description" because they involved a systematic cover-up.

The main scandal centred on allegations that police in Kanagawa prefecture covered up drug abuse by a former assistant inspector, Yoshihisa Sakayori.

Mr Sakayori had confessed in December 1996 to using amphetamines, but was not arrested despite a positive urine test for drugs. He was only fired after a subsequent extramarital affair.