Angela Cannings' husband Tery arrives at court in LondonANGELA Cannings, the Salisbury mother jailed for the murder of her two baby sons, has been freed after a Court of Appeal ruled the conviction was unsafe.

Mrs Cannings (40), of Waterloo Road, was serving a double life sentence for smothering seven-week-old Jason Cannings in June 1991, and four-month-old Matthew in November 1999.

Michael Mansfield QC, for Mrs Cannings, told three senior judges that the prosecution case depended on the evidence of controversial paediatrician Professor Sir Roy Meadow, whose theories on cot death and murder were severely criticised by the Court of Appeal earlier this year, when it cleared solicitor Sally Clark of killing her two babies.

In both the Cannings and the Clark cases, the main evidence came from Prof Meadow's 'three in one' theory - that one cot death in a family was tragic, two was suspicious and three was murder. At Mrs Cannings' trial, he also quoted a study that found that 58 out of 75 children proved to have been victims of smothering had also had a previous unexplained sudden illness, just like Jason and Matthew.

Mr Mansfield had said Prof Meadow's testimony at Mrs Cannings' trial was now in doubt.

"Without Meadow, this case would not have got off the ground," he said. "The Crown's case was fundamentally to depend on Meadow.

"Were the trial to take place now, it is unlikely the Crown would call him, and if they did, it would have to be with a health warning attached to it."

The jury was also told that Mrs Cannings had been charged with murdering her first child, Gemma, when she was 13 weeks old, in November 1989. These charges were dropped just before the start of the trial but Mr Mansfield said that, by introducing the child as "background information", the prosecution was using her as evidence.

"Gemma starts to come into the case not as a backdrop but as a previous unnatural event, essentially a criminal event," he said. "Consequently, Gemma became part of Prof Meadow's three in one argument and his rarity points."

During the six-week trial, 13 medical experts were called to give evidence to say Mrs Cannings' three children could have died from Sids, sudden infant death syndrome. Just two experts, Prof Meadow and Dr David Ward-Platt, concluded that the babies had been smothered.

Mrs Cannings' appeal also centred on new evidence that suggested her children might have inherited a genetic flaw that left them with a fatal allergy to cows' milk. All died shortly after being fed.