Police had to force entry into Douglas and Elizabeth Iggulden’s home in Portobello after a family member raised concerns that they had not been in contact.
Full-time carer Mr Iggulden, 88, was found dead while his wheelchair-bound wife had collapsed nearby.
Frail Mrs Iggulden, known to her family as Ella, relied entirely on her husband to care for her at their ground-floor flat in Adelphi Place.
She is now in a serious condition at Edinburgh Royal Infirmary.
Police are trying to establish when the former RAF serviceman was last seen – but a newsagent which he visited daily said he had not seen him for at least three days.
It is not clear at this stage how long ago he died and how long Mrs Iggulden, who was also in her 80s, had been unwell and unable to call for help.
William Iggulden, 91, who lives in Edinburgh, said his brother was a “breezy” and “fit” man who “loved his wife” dearly. He said: “They lived for each other. He was very happy with his wife. He was a very pleasant man, well mannered.”
Neighbours described him as a private, quiet man who would stop and say hello and was dedicated to caring for his wife.
Mrs Iggulden, who is understood to have suffered a stroke several years ago, was rarely seen out of the flat.
A worker at a nearby corner shop, who asked not to be named, said he would miss Mr Iggulden’s daily early
morning visits. “He would come in every day,” he said.
“He hadn’t been in for the last three or four days. I thought it was because his wife wasn’t well. He looked after her all the time. He was a very good man.
“He only came over here and then went home, I never saw him go anywhere else. He would buy cigars, papers and sweets. I will miss him.”
Witnesses described seeing six police cars, a fire engine and an ambulance rushing to the scene on Sunday afternoon.
Forensics experts attended at the address later that night while a lone police officer guarded the scene throughout yesterday. A police spokesman said: “The death continues to be treated as unexplained and a report has been sent to the Procurator Fiscal.”