During medical exams, doctors take note of the physical build and nourishment of the woman. Even among medical professionals, there are notions that a healthy woman would have been able to fight back her attackers, said Reddy, who has conducted sexual assault medical exams.

The notion is perpetuated in forensic medical textbooks, Deosthali said.

If a sexual assault survivor lacks obvious signs of injury, this may bias the case, because there is such an emphasis on finding injuries during the exam, Reddy said.

"It's not necessary to have injuries in sexual assault," he said. "The absence of injury doesn't mean she has consented."

Rape cases can lack obvious signs of harm, because the victim could have been unconscious, intoxicated or the assailant could have used lubrication.

The government-appointed panel warned against relying heavily on "the marks of struggle." It cited a law commission that said: "The Indian law of evidence does not, in general, lay down that a particular species of evidence should be insisted upon any proof or disproof of a particular fact."