Detectives say they are not looking for anybody else in connection with the discovery of two bodies by a window cleaner in Norfolk.
The man and a woman, aged 71 and 69, were found in a bungalow in the seaside town of Caister-on-Sea. The couple have not been formally identified but have been named locally as Barry and Jean Ellis who had lived in the area for about 30 years.
They were described by a neighbour as "lovely people".
Police forced their way into the property after a window cleaner spotted them while on his rounds. He had become suspicious after seeing milk bottles lined up outside.
A cordon remains in place at the house in Upper Grange Crescent while forensic checks take place.
It is not thought there were any obvious signs of a disturbance or injuries. One theory being investigated is that the couple suffered carbon monoxide poisoning from a faulty heating system.
Window cleaner Roy Holland, 39, called police at lunchtime on Tuesday after discovering the couple. He had cleaned their windows for more than a decade and said they had been a "lovely, friendly couple".
Mr Holland added: "I'm a bit overwhelmed by it all - it's a terrible thing to happen."