The accused Dharmendra, brother of 23-year-old Priyanka, reached her house this morning and scolded her for eloping with 25-year-old Harender.
Harender and Priyanka had a love marriage in Bihar's Ara district against the wishes of the family members, according to police.
Priyanka was a relative of Harender's elder brother.
"She used to visit his house and fell in love with him. Both decided to get married but their family was not happy with their decision. They secretly got married and fled to Delhi," said a police official.
Both of them taken to a hospital where Harender was declared brought dead and Priyanka is battling for life.