A doctor was arrested Monday on charges of indecent conduct against a woman when three male medical students allegedly gang-raped her in Chiba in September.

The Chiba Prefectural Police said they have arrested Yuji Fujisaka, 30, who belongs to Chiba University Hospital and is in a position of supervising the three students at Chiba University.

Fujisaka is suspected of indecency against the woman in her 20s who joined a drinking party also attended by the three students and Fujisaka at a restaurant in the city of Chiba on Sept. 20.

The police had arrested the trio on Nov. 21 and identified them Monday as Masaya Yoshimoto, 23, Kensuke Yamada, 22, and Mineto Masuda, 23.

The three allegedly gang-raped and injured the woman from the night of Sept. 20 and into the early hours of Sept. 21 at the restaurant and at Masuda's home. They and Fujisaka have admitted to the charges in principle, the police said. Fujisaka apparently did not go to Masuda's home.