Neighbours alerted by the dead woman's mother on Wednesday eventually forced their way into the flat, still adorned with festive decorations and unopened Christmas presents, to find the couple in their mid-twenties side-by-side with their son near by. Tests were still being carried out on the bodies yesterday to establish how they died but police said that "substances" - usually taken to mean drugs of some kind - had been taken away from the home in Rhyl.
Police visited the address twice, last Friday and Sunday, at the request of a relative, but received no reply and saw nothing that would have alerted them to the grim reality inside.
Many of the circumstances surrounding the deaths will become clearer today after the coroner has opened an inquest, though police were able to say that the couple, Tony and Elizabeth Walker, were last seen on 20 December, but had been dead for several weeks.
However, a source close to the inquiry said it appeared that the boy, Michael, died after his parents. A senior paediatrician estimated that he may have been conscious for 36 hours in a distressed state before lapsing into unconsciousness, coma and deathfrom dehydration, possibly as much as five days later.
The boy was discovered near the bodies of his father, a postman, and mother, who were in a kneeling position in the lounge of their first-floor flat above a hairdresser's salon.
Colleagues at Royal Mail's Rhyl delivery office, were Mr Walker had worked for slightly less than a year, said that he had last turned up for duty a few days before Christmas. Managers tried to contact him a number of times by mail, and eventually visited the flat, but were unable to get in because of the communal front door. Neighbours thought the family had gone south to visit relatives over Christmas.
David Edgington, a furniture store worker, who lives in the flat above, said Christmas decorations and the tree still adorned the lounge when he and the agent for the property broke in at the request of Mrs Walker's mother. A North Wales police spokesmanconfirmed that there was no evidence to suggest anyone else involved, though he said that only the tests would reveal if they had died accidentally, believed the more likely theory, or as a result of a suicide pact.
However, it is understood that officers had gone to the flat twice after calls from a relative in the South of England, asking if they could discover if the couple had moved from the address. After being told there was no reply, the relative went abroad on holiday.
Dr Donald Waite, Home Office pathologist, conducted post-mortem examinations at Glan Clwyd Hospital, Bodelwyddan, on Wednesday night, but the results of tests might take several days, police said. David Jones, the coroner, who will open the inquest at Prestatyn, said it "must be a possibility" that Michael died after his parents. "It is a dreadful situation if that is the case."