Fakurbano and her sons Sayan Abbas(7) and Hamza (2) were found dead in their house this morning, police said.
The woman's father alleged that the three were either strangulated or poisoned by his son-in-law Shakeel Abbas.
In the complaint, he claimed that Abbas had been harassing Fakurbano for dowry since their marriage in 2006.
The father who rushed to his daughter's house locked Abbas in a room and later handed him over to the police.
The bodies have been sent for post mortem and the matter is being probed, police said.