Police rule out carbon monoxide poisoning in deaths of husband and wife found in their bungalow Police forced their way into property yesterday in Caister-on-Sea, Norfolk Jean, 69, and husband Barry Ellis, 71, believed to have been dead for days Great Yarmouth MP Brandon Lewis says he was left 'shocked' by tragedy By Mark Duell and Anthony Bond Detectives investigating the deaths of an elderly couple found dead in their bungalow have ruled out carbon monoxide poisoning. The couple who have been named locally as Barry Ellis, 71, and wife Jean, 69, are thought to have been dead for several days before they were found. It is now thought they died of natural causes. Police are believed to be working on the theory that one of them might have died of shock after discovering that their spouse had died. The couple had been married for 50 years. Location: The bodies were discovered at a property in Caister-on-Sea, Norfolk, after police forced their way in The alarm was raised by window cleaner Roy Holland who got no reply when he called at their detached home at around noon on Tuesday and saw milk bottles building up on their doorstep. He peeped through the blinds on the front window and saw Mr Ellis, a retired market trader and driving instructor, slumped in a chair. Mr Holland, 39 alerted police who broke in through the front door and found the couple dead in their bungalow in Caister-on-Sea near Great Yarmouth, Norfolk. Officers at first suspected that the couple might have died from carbon monoxide poisoning due to a faulty heating system and called in Norfolk Fire Service to make sure the bungalow was safe. Firemen wearing breathing apparatus went into the two bedroom home and carried out tests for the gas with the specialist equipment before declaring it was safe to enter. Norfolk Police confirmed that a post mortem today revealed that the woman was believed to have died from natural causes. 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 Further toxicology tests are due to be carried out on the bodies, but sources suggested that Mr Ellis was also likely to have died from natural causes. A Norfolk Police spokeswoman confirmed that officers were not looking for anyone else in connection with the tragedy. She added: 'Neither of the deaths are being treated as suspicious. Formal identification is still due to take place and a file has been passed to the Coroner with an inquest opening in due course. There is no evidence to suggest at this time that either death was due to carbon monoxide poisoning. The bungalow which is about a mile from the sea remained sealed off today while a police investigation into the deaths of the couple continued. It is believed that there were not any signs of a disturbance in the bungalow or obvious injury to the couple. Investigation: Officers are awaiting the results of post mortems on the couple which were being carried out on the couple 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. 'I tried phoning them, but I couldn't get any reply. He is dead Neighbour Geoffrey Sutton, 74 They had quite a job breaking the door down. 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. 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. Window cleaner Mr Holland, 39, who first raised the alarm, described Mr and Mrs Ellis as a 'a lovely, friendly couple'. He said: 'It was quite a shock. It's not something which you like to see - it's a thought that won't go away for quite a while. 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 You get to know your customers and if they are in or out. Both cars were in the drive. There were six pints of milk on the doorstep and the neighbours said they hadn't seen them for days. I then decided to take a look through the window and saw the gentleman sitting in the chair. They never went anywhere without each other so if the gentleman was in, it was likely his wife was at home too. Mr Holland said he had cleaned the couple's windows for around ten years and had never known them to go away on holiday. He added: 'I am a bit overwhelmed by this. It's a terrible thing to happen.' Mr and Mrs Ellis who are thought to have lived in their bungalow for around 30 years used to run a stall selling clothing and underwear at Great Yarmouth market. Thoughts with families: Great Yarmouth MP Brandon Lewis told MailOnline he was 'shocked' A fellow market trader said: 'They were very quiet and did not mix with a lot of people. I think they must have given up their stall about ten-years-ago. They were here for quite a few years. A neighbour of the couple said Mr Ellis had previously worked as a driving instructor. The couple are thought to have celebrated their Golden Wedding anniversary after 50 years marriage last year. 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. I am really shocked. 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. The normally peaceful coastal village of Caister-on-Sea popular is popular with holidaymakers for its long sandy beach and is home to many retired people. Brandon Lewis, the MP for Great Yarmouth constituency, which includes Caister, said he was shocked by the deaths. The Conservative MP, a minister in Eric Pickles" Department of Communities and Local Government, said: 'This sounds like a terrible tragedy and my first thoughts are with the families of the deceased. I shall be keeping informed of events.