Poti Reddy (70) and his wife Lakshmamma (65) were killed in the wee hours in the house of Madanmohan Reddy, a former legislator, in Rajampet town near here, they said.
Poti Reddy was working as a cook in the house of Madanmohan. The family members of Madanmohan were not in the house when the blast took place.
The explosion led to the collapse of the roof on the couple, who died instantly, they said.