New evidence in the case of a solicitor wrongly jailed for killing her two sons would make it almost impossible for a jury to convict her, the Court of Appeal has said.
Sally Clark had always protested her innocence
The court took the unusual step on Friday of revealing full details of why Sally Clark's convictions were quashed.
Mrs Clark, 38, was freed in January after three judges ruled that her convictions were "unsafe" and that she did not have a fair trial.
Mrs Clark, who had always protested her innocence, was convicted of the murders in November 1999 at Chester Crown Court.
She was accused of killing her 11-week-old son Christopher in December 1996 and eight-week-old Harry in January 1998 at the home she
shared with her husband Steve in Wilmslow, Cheshire.
Lord Justice Kay, giving the court's reasons for overturning her conviction said the Crown
had taken the "right and proper course" not to seek a retrial.
The judge said: "We would have taken a great deal of persuading that on the state of the evidence as we now know it to be, any jury could properly have been sure that either or both of these children were murdered."
Lord Justice Kay, sitting with Mr Justice Holland and Mrs Justice Hallett, added: "When the medical evidence is as divided as it is in this case, it seems to us that it would in all probability be impossible, even if the case was reheard, to reach a conclusion with the required degree of certainty about this matter."
Mrs Clark was not present at the hearing, but issued a statement thanking the judges for their "wisdom and sense of justice".
During the appeal, the judges were told that crucial medical evidence relating to Harry, which could have cleared Mrs Clark of the murders, was not disclosed to the defence team and only emerged at the end of 2000.