There is a "likelihood" a two-year-old boy might still be alive if his father had not suffered a fatal heart attack over Christmas, a pre-inquest hearing has heard.
Bronson Battersby was found between the legs of his dead father, Kenneth Battersby, on 9 January in their home in Skegness, Lincolnshire.
Circumstances suggest Bronson died after his 60-year-old father, coroner Jayne Wilkes told the pre-inquest review hearing at Greater Lincolnshire Coroner's Court on Thursday.
"There has to be a likelihood that had Kenny not passed away then Bronson would still be alive," she said.
"At present, we do not have any clear factual basis as to when Bronson passed away. He was of course pronounced deceased on 9 January, but that is not, on the information we have been provided so far, likely to be the day he died.
"We may never have sufficient information on when Kenny or Bronson passed away and Kenny's death is clearly important as a supporting or overlapping feature we also need to investigate."
Bronson lived in a basement flat in Prince Alfred Avenue with his father, who had separated from the boy's mother.
A neighbour had called the police to report she had not seen Mr Battersby for several days and a smell was coming from the flat, an inquest opening was told in June.
Mr Battersby's death was determined to have been caused by a "sudden cardiac event" because of underlying heart disease, the coroner told the hearing.
A post-mortem examination of Bronson "notes low body fat and muscle" and he appeared malnourished, Ms Wilkes said.
His cause of death was recorded as dehydration.
There had been "limited food in the fridge," Ms Wilkes said, and other food items in the freezer were "obviously of no use to Bronson".
Lincolnshire County Council said Bronson had been known to children's services and he would typically be seen by social workers at least once a month.
A spokesperson for the council said a social worker contacted Mr Battersby on 27 December and arranged to visit on 2 January, but there was no response when they arrived.
Selfies taken by Bronson on 31 December and Mr Battersby's financial accounts are among the pieces of information needed to create a timeline of their deaths, the coroner said.
The Independent Office for Police Conduct (IOPC) investigated Lincolnshire Police's involvement before the deaths. In September it said there was no indication any officer or staff member breached professional standards.
Ms Wilkes said the full inquest into the boy's death is unlikely to take place before early autumn next year.
(c) Sky News 2024: Bronson Battersby: 'Likelihood' boy, 2, would have survived if father had not died in flat,