A house where an elderly man and woman were found murdered showed signs of a struggle, police have said.
Terence and Vera Martin had lived in Abbey Street all their married life
The bodies of the couple, Terence Martin, 72, and his wife, Vera, 78, were discovered in Abbey Street, Faversham, Kent, on Wednesday.
Detectives are examining whether they were the victims of a bungled robbery.
Post-mortem examinations are due to be carried out at the William Harvey Hospital in Ashford, after which the couple should be formally identified.
They were described by neighbours as a devoted pair who often walked holding hands.
A card on one bouquet of flowers left at the scene read: "The sweetest and most loving couple anyone has ever known."
The bodies of the couple have been removed from the house
Det Ch Insp Dean Barnes described it as an "extremely distasteful crime".
He said there were no signs of a forced entry into the house, but it appeared to have been searched.
"It could be a burglary gone wrong. This is something which is currently being investigated.
"There are a number of lines of inquiry we are still pursuing."
Mr Barnes described the couple as frail, adding that more than one person was probably involved in a struggle with them.
Police investigations are also continuing into the discovery of their car.
The purple Daihatsu Sirion was found burned out just over a mile away from their home in the Bysing Wood Road area of the town on Monday evening.
"It appears the vehicle may have been abandoned as a consequence of what went on at the house earlier on," said Mr Barnes.
The couple's burned out car was taken away for forensic tests
He said police officers knocked at the couple's house soon after their car was found, but "there was nothing that would draw their attention to anything untoward".
He added it was now "common sense" that they were already dead at the time.
Mr Barnes said: "We want to talk to anyone who may have seen the couple anytime from Saturday afternoon onwards in or around their home.
"We also need to locate where their car travelled from until it was found burned out on Monday evening."
Local Conservative MP Hugh Robertson has urged the police to bring the killer or killers to justice as soon as possible.
He added that he would be doing everything he could to reassure the local community.