Japanese police said on Thursday they arrested a former taxi driver on suspicion of drugging and raping a female passenger, with media reports saying there could be dozens more victims.

The Yomiuri Shimbun daily and Jiji Press reported that police found about 3,000 videos and images of him sexually assaulting around 50 women in his taxi or his home.

Last year, the man “got a woman, then in her 20s, to take sleeping pills which caused her to lose consciousness, took her to his home and committed an indecent act, which he filmed,” a Tokyo police spokesman told AFP.

Police arrested the 54-year-old on Wednesday on “suspicion of non-consensual sexual intercourse and violation of the law on punishment of filming of sexual parts,” he added without elaborating further.

Traces of sleeping pills were detected in her hair, according to media reports.

The footage recovered on the man’s phone and other devices dated back to 2008, the reports said.

Media also said that he was arrested last October on suspicion of drugging another woman and robbing her of 40,000 yen ($280).

He was later released before being taken into custody again in December for alleged indecent assault, the reports said.