Six people have been detained for allegedly sexually assaulting a 21-year-old Russian woman who is in Tiruvannamalai on a tour, police said on Wednesday.
The woman was found unconscious in a service apartment on Monday and was taken to a hospital by one of the six men who are being questioned.
On examination, the doctors found injuries on her body, including bite marks, and alerted police, they said.
Police suspect that the foreign national lost consciousness under the influence of some drug, the nature of which was not known immediately.
The woman, who is Tiruvannamalai for about a week, has regained consciousness and investigation is underway, the police added.
Tiruvannamalai is a popular temple town in the state about 190 km from Chennai.
The incident comes against the backdrop of the alleged rape of an 11-year-old hearing-impaired girl by 17 people over the past seven months in her apartment complex in Chennai.