He saw Mr Ellis, who is believed to have been a retired driving instructor, slumped in a chair. The window cleaner alerted police who broke in through the front door and found the couple dead.
Firemen wearing breathing apparatus also went into the two-bedroom home to make sure that it was safe before police investigators and paramedics went inside. The house remained sealed off today.
Norfolk Constabulary said the deaths were still being treated as ‘unexplained’, but added that the force was not looking for anyone else in connection with the tragedy.
It is believed that there were not any signs of a disturbance in the bungalow or obvious injury to the couple, indicating they were possibly killed by carbon monoxide from a faulty heating system.
‘I knew something was wrong when I saw all the police, fire and ambulance vehicles at the scene. They were a very quiet couple and their deaths are a mystery. I am really shocked’
Neighbour David Dyer, 62
Officers are awaiting the results of post mortems on the couple which were being carried out today and were trying to trace their next of kin.
Retired draughtsman Geoffrey Sutton, 74, who lives next door to the couple said: ‘It is a terrible tragedy. They were a lovely couple who were devoted to each other. I had not seen them for a week or two and I had assumed they were staying in during the cold spell.
‘The window cleaner realised something was wrong when he called round to do their windows. He couldn’t get an answer so he came round to see me.
‘I think there were about six pints of milk on the doorstep. I tried phoning them, but I couldn’t get any reply. The window cleaner then peered in the window through a gap in the venetian blinds and said, “I can see him. He is dead”.
‘The police arrived and called through the letter box to see if they could raise anyone in there and they thought they could smell gas. They had quite a job breaking the door down.
‘I tried phoning them, but I couldn’t get any reply. The window cleaner then peered in the window through a gap in the venetian blinds and said, “I can see him. He is dead”‘
Neighbour Geoffrey Sutton, 74
‘I know Barry was pretty security conscious so his home was very secure. I saw a couple of firemen go in with breathing apparatus and I overheard some discussion at the scene that it might be a case of carbon monoxide poisoning.
‘I know that they had an oil-fired central heating system so it looks like that was the reason for their deaths. It is very sad. They always went out together and they never seemed to have any visitors.
‘They just kept themselves to themselves. I don’t think they had any children, but I recall Jean saying that she had several brothers and was the only girl in her family. They had lived in the bungalow for many years.’
Concern: The alarm was raised by a window cleaner who, after receiving no reply when he called and saw milk bottles lined up on their doorstep, looked through the blinds on the front window
David Dyer, 62, who lives opposite, said: ‘I knew something was wrong when I saw all the police, fire and ambulance vehicles at the scene. They were a very quiet couple and their deaths are a mystery. I am really shocked.’
Detective Inspector Sarah Pettengell of Norfolk Constabulary said: ‘Police were called to the property on Upper Grange Crescent at lunchtime yesterday following concerns for the safety of the occupants.
‘After officers forced entry, a man and a woman were found deceased inside. The house has been sealed off whilst officers investigate the circumstances of the deaths.
‘Whilst the deaths are currently being treated as unexplained, we are not looking for anyone else in connection with them. We are continuing to carry out inquiries at the house and the focus of our investigation is inside the property.’
Norfolk Fire and Rescue Service spokesman Martin Barsby said: ‘We sent a heavy rescue pump vehicle carrying gas analysis equipment to the incident.
‘We needed to check that it was safe for police and paramedics to enter the property.’
Caister-on-Sea – which has an average house price of £150,000 – has been a settlement in some form since the first century, and is a popular destination for holidaymakers thanks to its sandy beaches and caravan sites.
Great Yarmouth MP Brandon Lewis told MailOnline: ‘I was shocked to hear about the deaths of Mr and Mrs Ellis. My first thoughts are with their family at this difficult time.
‘I have been kept in regular contact by Norfolk Constabulary who are dealing with the case and I have every confidence that they will get to the bottom of this tragic situation.’