A former Congress member of parliament, his wife and their son have been detained for questioning about the death of the ex-MP's daughter-in-law and three grandsons in a fire at his house on Wednesday in Telangana's Warangal town.
Siricilla Rajaiah, his wife Madhavi and son Anil Kumar were picked up from their house and taken an undisclosed location under tight security.
Rajaiah represented the Warangal Lok Sabha constituency in the undivided Andhra Pradesh.
Police said the former MP, his wife and son were present when the fire broke out in then first floor bedroom of the house in the early hours of Wednesday, and killed the woman and her three small children.
Police are investigating the cause of fire.