Sonia, a student of BA Final year, had allegedly eloped with her boyfriend of same village on May 9.
However, both were found by police two days later from Gurgaon railway station on the basis of complaint filed by girl's father Ravi Dutt.
Sonia was handed over to the family by the police, they said.
However, she died under mysterious circumstances on May 19 and her family cremated the body next day without conducting postmortem, police said.
Ravi Dutt and Krishan Saini were arrested, police said, further investigation is underway.