A Frenchman was in custody tonight suspected of killing his British expat neighbour and throwing his body down a well in rural Normandy. David King, 70, and originally from east London, had not been seen for six months in the picturesque hamlet of Pierres, in the Calvados department, south west of Caen. He retired there from his job as an engineer in Britain some 15 years ago. On October 27, he went to tea with friends living close to his home, and is thought to have got into an argument with one, aged 28. Disappeared: David King, 70, had been missing for six months from his home in Normandy, France . Carole Etienne, the Caen prosecutor, said: 'He admitted there was an argument, and to putting the body in the well. In the coming hours we will try to learn more about what caused the death.' Ms Etienne added: 'We're no longer following a missing person's enquiry, but one for manslaughter because of the presence of unusual clues. 'Inconsistent explanations' and DNA analysis all led investigators to 'suspect someone in connection with a killing', said Ms Etienne. 'He has not yet explained the circumstances of the death,' said Ms Etienne. I have the before, I have the after, I don't have the in-between.' Mr King had been living in France for 15 years . Ms Etienne said the suspect had not yet been identified publicly. On Wednesday police sniffer dogs were taken to Mr King's hamlet, and found his corpse at the bottom of the 12ft well. Mr King lived alone, but regularly kept in touch with family, including grandchildren in the UK, said another source close to the investigation. It is believed he has in son in Brighton, East Sussex and a daughter in Australia, who French police initially thought he was visiting after his disappearance last year. He was known to have a heart condition, and there were concerns that he had travelled away without his medication. Other theories included suicide, but his family did not believe it, as they had been looking forward to seeing him at Christmas. It was also suggested that he might have gone to see his daughter in Australia, but this was ruled out too because a passport was found at his home. International organisations including the Lucie Blackman Trust were involved in trying to solve the mystery, posting pictures of Mr King online. His disappearance 'caused a great deal of fear' among British expats living in the area - one which is very beautiful but also extremely isolated, said the source. In February, Mr King's car, a Renault Scenic was found parked in Vire, a nearby town, but there was no sign of any body. A friend told The Independent: 'We had grown used to the idea that we would never see Dave again but this is the worst possible outcome to the mystery.' Mr King was a keen gardener who chose to settle in an area popular with older British expatriates. Autopsy results are expected to be announced on Friday. Discovery: Police had thought he was in his car (pictured), but his body has now been found down a well. Mr King's 28-year-old neighbour is now in custody being questioned about his death .
David King had not been seen since he went to tea with friends in October .
The 70-year-old is thought to have got into an argument before his death .
Prosecutor said a neighbour admitted to putting Mr King's body in the well .
But the man has yet to explain 'the circumstances of the death'