Doubts over conviction of mother for babies' murder

New evidence has cast doubt on the conviction of a mother for murdering two of her babies who were initially thought to be victims of cot death.

Angela Cannings is serving two life sentences after being found guilty last year of smothering seven-week-old Jason in 1991 and 18-week-old Matthew in 1999.

Both boys died while in the care of Cannings. Their deaths were put down to cot death until experts concluded that they had been murdered.

An investigation has now suggested that the boys may have inherited a genetic flaw which meant they were born with a fatal allergy to cows milk. They both died within hours of being given cows milk.

Cannings' first-born daughter Gemma died at 13 weeks in 1980 while she was being bottle fed. Cannings was accused of murdering Gemma, but the charge was dropped at the start of the trial.

Cannings' 21-month-old half brother Joshua Connolly has since been diagnosed with the same allergy after three near-death respiratory attacks in his first year. Experts have suggested that cows milk might be a cause of cot death because it is the first foreign body that a newborn baby's immune system has to cope with.

Cannings' family also has a history of cot death. Her grandmother lost two babies to the syndrome, her great-grandmother lost one child and two of her cousin's babies also died from what is believed to be the same syndrome. This history was not presented at the trial.

Cannings' appeal against her conviction is due to be heard next week, and involves the evidence of the paediatrician, Professor Sir Roy Meadow. The case has been fast-tracked after Sally Clark, a solicitor, won an appeal against her conviction for murdering her two sons.

Sir Roy gave evidence in the trials ofCannings and Mrs Clark, as well as that of Trupti Patel, who was cleared in July of murdering her three babies. Sir Roy's theory, known as Meadows Law, was vital to the prosecution's cases. He stated that one cot death in a family was a tragedy, two was suspicious and three was murder.

In Mrs Clark's trial, Sir Roy testified that the odds of two natural cot deaths occurring in one middle-class, non-smoking family were one in 73 million. When three law lords quashed Mrs Clark's conviction in January, they criticised Sir Roy's evidence as "manifestly wrong" and "grossly misleading". Evidence that one of Mrs Clark's sons had been suffering from an infection which could have caused his death had also not been disclosed by the prosecution.

Sir Roy's testimony in a number of cases is now being reviewed, and the General Medical Council is believed to have launched an investigation into complaints against him.

At Cannings's trial, Sir Roy told the jury that she had probably smothered her babies. The prosecution offered no motive for the murders. Sir Roy told the court: "For me, the unusual feature is death so soon after being seen so well."

However, in another case in which his testimony helped convict a mother of murdering two babies, Sir Roy said that the case was suspicious because the children had been ill beforehand.

Cannings, 40, is serving her sentence at Bullwood Prison in Essex. Her husband Terry says she is innocent, although he is cautious about the chances of the appeal succeeding. The evidence on her case will be shown in a BBC 1 documentary, Real Story, tonight.