TOKYO Wealthy property developer Joji Obara pleaded not guilty on Tuesday to drugging and raping three Japanese women in what could be Japan's worst serial rape case.

Obara, 48, also under investigation in the death of blonde Briton Lucie Blackman, whose dismembered body was found two weeks ago in a seaside cave near one of his homes, insisted at a Tokyo court that the women agreed to have sex with him.

"These were women I met through telephone dating clubs for the purpose of fun, or paid sex," the bearded Obara, dressed in a gray suit and a black sweater, told the court.

"The sex play with them was based on mutual agreement. I didn't use drugs."

Tuesday was the second hearing in a case that has sparked a frenzy of media attention.

Obara faces five charges of raping Japanese and foreign women and was arrested on a new charge last month involving sexual violence resulting in death for allegedly drugging and raping an Australian woman in 1992.

Police have collected more than 10,000 pieces of evidence that include videotapes of Obara allegedly assaulting and raping women he lured to his apartment and made unconscious with drinks spiked with knockout pills or chloroform.

Obara has denied any involvement in Blackman's disappearance and death, but police have continued their investigation for possible links.

The 22-year-old from Sevenoaks, Kent, was working at a hostess bar in Tokyo's Roppongi Entertainment District and vanished after saying she was going for a drive with a man on July 1.

Quoting police sources, Kyodo news agency said authorities planned to arrest obara over Lucie's murder after pinpointing the cause of her death by examining her internal organs.

(Reuter)