Diabetes theory over salt death
The BBC has found fresh evidence which could cast doubt on the convictions of a couple jailed for killing a three-year-old boy they hoped to adopt.
Ian and Angela Gay, from Halesowen, West Midlands, were found guilty of the manslaughter of Christian Blewitt by poisoning him with salt.
But the BBC has found he could have been suffering from a rare form of diabetes which affects salt levels.
Prof Ashley Grossman, of Barts Hospital said it could not be ruled out.
Prof Grossman, a professor of neuro-endocrinology, said: "On the basis of the data that I've seen, I just cannot see how you can exclude that diagnosis.
"Although it's a rare condition, the deliberate harming of a child by giving them massive amounts of salt, on a single occasion, seems to me an even more bizarre occurrence."
The couple, who are hoping to appeal against their convictions, were found guilty of Christian's manslaughter in January and jailed for five years each.
The youngster died in hospital in December 2002 after falling unconscious at their former home in Bromsgrove, Worcestershire.
As there had been no sign of a drip in Christian's body, the prosecution had assumed the couple had forced a lethal dose of salt - four and a half teaspoons - into his mouth.
Diabetes insipidus makes the salt level in the sufferer's blood go haywire, causing them to lose large amounts of water.
'Makes better sense'
Professor Grossman said this could account for the difficulty experts had had in explaining why doctors had been unable to bring down the salt level in Christian's blood.
He said: "If you're salt intoxicated [poisoned] then the body should try to rectify itself, so diabetes insipidus makes better sense in the fact that the child failed to improve quickly."
A third assumption by the prosecution was that no genetic disease was to blame for Christian's death whose family history was not known. Tests on his brain and kidney showed they were normal.
But File On 4 has seen paperwork which diagnosed him with hydrocephalus - water on the brain which can damage the pituitary gland and trigger diabetes insipidus.
Jackie Gay, Ian Gay's mother, said: "When the defence pathologist and the other two post mortems asked for either the pituitary gland or the results of the tests carried out on it - it was never tested and there was no pituitary gland.
"It was missing. Nobody knows what happened to it."