A COUPLE jailed for killing a boy of 3 by force-feeding him with up to six teaspoons of salt as a punishment were wrongly convicted, three Court of Appeal judges were told yesterday.

The jury at the criminal trial in January last year of Ian and Angela Gay, who wanted to adopt Christian Blewitt, was not given the opportunity to consider whether he died from natural causes.

Michael Mansfield, QC, their counsel, said that, since the trial at Worcester Crown Court, a report by Glynn Walters, a specialist consultant in medical pathology, challenged expert evidence given to the jury.

Dr Walters will give fresh evidence to the appeal court today that the osmostats — likened to thermostats in the brain, which regulate sodium concentration in the body — can malfunction and reset at levels that are too high.

New evidence would say that the child was one of only a handful of documented cases known to medicine to suffer from hypernatraemia, an excess of salt in the blood leading to cerebral oedema.

Dr Walters had concluded, he said, that “there is nothing in this case that can be explained by salt poisoning that cannot be equally well explained by resetting of the osmostats”.

The couple sat behind bars in Court 8 at the High Court, the first time that they had met since their conviction for manslaughter, as Mr Mansfield began an application for leave to appeal.

The Gays were charged with murder after doctors found serious head injuries on Christian’s body; manslaughter over the salt poisoning; and child cruelty. After a seven-week trial they were acquitted of the murder charge and the judge discharged the jury from giving a verdict on the cruelty charge.

But they are serving five years for the manslaughter of the little boy, who swallowed the equivalent of a litre of seawater.

Christian was the eldest of three siblings placed with the wealthy couple at their home in Bromsgrove, Worcestershire. Mr Gay, 39, an engineer, and his wife, 40, a £200,000-a-year insurance actuary, wanted to adopt all three. The other brother and a sister have been successfully adopted elsewhere.

The three had been with the family for about three weeks when Christian was taken to Russells Hall Hospital on December 8, 2002, after lapsing into a coma. He was transferred to a special unit at Birmingham Children’s Hospital that night but died four days later when his life support machine was switched off.

Mr Mansfield said that jurors at the criminal trial of the couple had had to grapple with a mass of contradictory expert evidence over the cause of death. They were presented with two options: either the couple murdered the boy with a blunt instrument, which led to the unexplained head injuries, or were guilty of manslaughter through feeding him salt.

But Mr Mansfield asked the appeal judges — Lord Justice Richards, Mr Justice Penry-Davey and Judge Ann Goddard — to hear a third option, that he had a rare brain malfunction that allowed sodium levels to overload. The condition, he said, could explain why the boy was retaining sodium instead of excreting it via his kidneys, which were functioning normally.

Mr Mansfield told the court: “These two individuals had an unblemished character. They were just two ordinary adults who wished to adopt because they were unable to have children of their own. There was no prior misbehaviour or abuse.

“The issue at their trial was broadly a whodunnit, but, more importantly, a whatdunnit.” He added: “One has to be very careful in medical cases — and I don’t hesitate to say that this case is at the frontiers of science.

“It has to be countenanced that there was an unknown existing disorder (suffered by the boy) at the time. What is regarded as truth and accepted litany today is regarded as heresy tomorrow.”

William Davis, QC, for the Crown, denied that Dr Walters’s evidence was new or that it was a “burgeoning area on the frontiers of science”.

He said that the Crown had not failed to put forward an explanation at their trial of how the couple might have killed the boy. In cross-examination the couple had been asked about injuries to the boy’s chest wall, underneath the arms and asked whether this occurred while one held the boy down and the other fed him with salt. The couple had denied those allegations.

Of the evidence that Dr Walters was to give, Mr Davis said this was not fresh testimony but a revisiting of what was litigated at trial.

The hearing continues.

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