The victim's father, a resident of sector 6 in Dharuhera, complained that one Mithun, a worker who used to stay in same building as a tenant and hailed from Bihar, frequently sexually exploited her for the past several months, police said.
The matter was revealed when the girl complained of pain in abdomen and on examining she was found pregnant, they said.
On the basis of the complaint, an FIR was registered on Thursday under various sections of the IPC and POCSO Act against the accused, they said.