Lajpat, a resident of Hem Nagar here, was arrested yesterday, they said.
The accused was arrested after Jayabir Gehlawat, member of a human rights group here, informed the CJM and DSP that the minor girl was being forced to work as a slave at Lajpat's house and was not even given food, police said.
Following the complaint, a raid was conducted at Lajpat's house and the girl was rescued, they said.
The victim alleged that Lajpat had bought her from Punjabi Bagh in Delhi and made her work like a labourer. She also alleged that Lajpat had sexually assaulted her repeatedly, police said.
The victim has been sent for medical examination, police said.