"Special teams are on the job and the culprits will soon be apprehended," a senior police official told news agency Press Trust of India. "The probe is still at preliminary stage," he said adding several people are being questioned.
The medical report revealed the accused wore a condom as he sexually assaulted the woman, sources said. "It's all the more challenging and we are taking whatever the victim says," an investigator, who requested not to be named, said.
The German woman has said that she was raped on a deserted beach near Tiger Caves outside Mahabalipuram where she was sunbathing. In her complaint to police, she said two men accosted her but only one sexually assaulted her.
A member of the German national's tourist group said, "Both were Indians. Police are investigating in a professional way."
Following the incident, security has been increased around the tourist destinations in Mahabalipuram including, the world heritage site of Shore Temple.
(With inputs from PTI)