Warangal: Former Congress MP Sircilla Rajaiah and his wife and son were taken into custody on Wednesday hours after bodies of his daughter-in-law and three grandsons were found charred to death at his residence here in mysterious circumstances in the early hours today.

The police have registered a case of abetment to suicide against Rajaiah, his wife and son, but said they had not made any arrest so far in connection with the incident.

Media reports had earlier said that the trio have been arrested.

S Sarika and her all three sons - Abhinav, 7, Ayan, 3, and Sriyan, 3 - were burnt to death in the fire that broke out in her bedroom on the first floor of the house.

Fire brigade officials extinguished the fire around 6.30 am.

Also Read: Daughter-in-law, three grand children die in mysterious fire at ex-Congress MP's house in Telangana

While some reports claimed the fire started after an LPG gas leak, others said it was started by Sarika.

Police found an LPG cooking cylinder with its regulator open was found in the room.

Warangal City Police Commissioner G Sudheer Babu said Rajaiah, his wife Madhavi and son S Anil Kumar were among those inside their house when the incident happened on the first floor of the two-storey building at Hanamkonda.

"Following a complaint by Sarika's parents, a case was registered against Rajaiah, his wife Madhavi and son Anil Kumar at Subedari police station under sections 498A (husband or relative of husband of a woman subjecting her to cruelty) and 306 (abetment to suicide) of IPC, and under section 174 (suspicious death) of CrPC for the death of three boys," a senior police officer said.

Police had questioned Rajaiah and Anil during the day.

The complaint alleges that Anil and his parents harassed Sarika. It also says that Anil didn't take care of her and had extra-marital relationships.

City Police Commissioner G Sudheer Babu said, "We are waiting for FSL report. Once FSL and post-mortem reports comes tomorrow then we will have a clarity on how the deaths occurred."

Sarika's mother and sister had earlier alleged in their native Nizamabad district that her in-laws "tortured her and killed her".

"My sister cannot commit suicide...She was tortured and killed," Sarika's sister alleged.

Incidentally, a criminal case was filed against Rajaiah, Madhavi, Anil and another woman, at the Begumpet women's police station in Hyderabad in April 2014, following a complaint lodged by Sarika, who alleged that her husband and in-laws had been harassing her for dowry.

Last year, she had staged a sit-in in front of Rajaiah's house, seeking justice for her and her children.

Rajaiah immediately withdrew from the Warangal Lok Sabha by-election in which he was a candidate.

The Congress had last week named Rajaiah as its candidate for the November 21 by-election from the Warangal Lok Sabha seat. He was elected from Warangal in 2009 but lost last year.

The party has now named former union minister Sarve Satyanarayana as its candidate from Warangal.

Anil and Sarika had met while studying engineering in Hyderabad and went for a registered marriage in 2002. A traditional marriage ceremony was later held with the consent of both the families in 2006.

(With agency inputs)