Preeti, hanged herself from a ceiling fan yesterday following marital discord with her husband Manish, they said.
As per the complaint of victim's brother Rajesh Chabra, she had frequent altercations with her husband since they got married last year.
Chabra has also accused his brother-in-law of having illicit relations with another woman, which forced Preeti to take the extreme step, police said.
A case has been registered against Manish and further investigations are on, they added.