Police said Rohit Lamba (41) had allegedly committed suicide on February 7 by hanging himself.
They said Rohit's father RL Lamba approached police on February 13 with a complaint alleging that his daughter-in-law was responsible for his son's death.
A case under sections 306 (abetment of suicide) and 34 (acts done by several persons in furtherance of common intention) has been registered on a complaint of Rohit's father, said a senior police officer.
RL Lamba alleged that his daughter-in-law was having illicit relationships, and she was trying to pass off his son's murder as suicide, he said.
Police are investigating the matter and family members are being questioned.