Angry that his wife Bandana Saha intervened to stop quarrel between him and his father, Gopal Saha and his sister beat her up severely, police said.
Gopal's parents also joined in the beating of the girl, who was later allegedly strangled with a pillow, the police said.
After killing the girl, her in-laws then tried to make it a case of suicide by hanging. Gopal and his parents were arrested after an FIR was lodged at the Dhantola police station, under which the area falls.
On persistent questioning by the police which found no sign of hanging, the girl's mother-in-law, Jyotsna Saha, purportedly admitted that she and others had strangulated her, police said.