The incident came to light on Wednesday evening when the victim was found unconscious in Najafgarh by a passerby.
Police took the victim, who had left her home to get her marriage registered without her parents' knowledge, to a hospital where a medical examination confirmed the sexual assault. She and Inderjeet got married in a temple without informing their families.
The victim claimed she was served cold-drinks laced with sedatives allegedly by Inderjeet, and his relatives Nitin and Vijender - all in their early 20s - then allegedly raped her. The trio have been arrested.
Inderjeet allegedly asked her to come to Delhi from her house in Jhajjar in Haryana to get their marriage registered.
"She told us that after she became unconscious, they allegedly raped her," a senior police official said.
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