Abuse is becoming particularly more common in places of religious tourism, according to the study by non-governmental organisation Equations.
Children interviewed said the abusers were foreign and domestic tourists, as well as local residents.
Civil rights groups say there is an urgent need for the government to address the issue.
The study was carried out in the temple towns of Puri in Orissa, Thirupathi in Andhra Pradesh and Guruvayoor in Kerala. More...