The accused, identified only as Ganesh, is a driver and the victim eloped with him after he assured her of marrying her, they said.
The teenage girl is the resident of Sabbavaram area in the district, police said.
The girl eloped with the accused on January 31 and the duo stayed at a lodge near Lankelapalem under Parawada block where Ganesh allegedly sexually assaulted her.
However, Ganesh allegedly went back on his word to marry her, following which the girl returned her home last night.
Police said the girl was sent to King George Hospital for medical examination and a search is on to trace the accused.