Babies the former nurse was convicted of killing were in fact victims of ‘bad medical care’ or died of natural causes, panel says. Babies the former nurse Lucy Letby was convicted of murdering were in fact the victims of “bad medical care” or deteriorated as a result of natural causes, an expert panel has concluded. Outlining what the senior Conservative MP David Davis described as “one of worst injustices of recent times”, the international team told a press conference there was “no medical evidence” to support claims of deliberate harm.

A panel of experts, chaired by Dr Shoo Lee, examined the cases of 17 babies whom Letby was charged with murdering or harming at the Countess of Chester hospital in north-west England. Lee, an emeritus professor at the University of Toronto, said the 14 experts had found “so many problems with the medical care” of the babies and nothing to support the claim they were attacked. “In summary, ladies and gentlemen, we did not find any murders,” he told a press conference in Westminster on Tuesday.

The press conference came as the Criminal Cases Review Commission (CCRC), the body that investigates potential miscarriages of justice, announced it had received a “preliminary application” from Letby’s legal team. A CCRC spokesperson said it was not possible to say how long it would take to come to a decision on whether to refer the case back to the court of appeal, which it can do if it believes there is a real possibility the convictions will be quashed.

Letby, now 35, is serving 15 whole-life prison terms after being convicted of murdering seven babies and attempting to kill another seven at the Countess of Chester hospital. She has twice been refused permission to appeal against her convictions by the court of appeal. A public inquiry is under way on the basis that she is guilty. Letby was convicted of murdering each of the seven babies by injecting air into their bloodstreams and attempting to kill several others by the same method. She was also convicted of harming two babies by poisoning them with insulin, pumping air into their feeding tube, force-feeding one with milk, and causing trauma to the abdomen.

Lee said the prosecution’s claim that Letby had injected air into babies’ bloodstreams had “no evidence in fact”. For the first time, experts suggested what they described as plausible alternative explanations for the deterioration of the infants – but ruled out deliberate harm. Lee, who chaired the panel, said the deaths and near-deaths were the result of failures in their care. In one example, he said the panel had concluded that Child 1 – a one-day-old twin boy Letby was convicted of murdering by injecting with air – had in fact died as a result of thrombosis due to a failure to begin his infusion until four hours after he was intubated, risking the development of clots.

Another baby, a 10-week-old girl whom Letby was convicted of murdering on her fourth attempt, in fact died as a result of complications linked to respiratory distress system and chronic lung disease, the panel concluded. Lee claimed doctors had failed to respond to routine warnings about her deterioration and did not treat her with appropriate antibiotics. He added: “This was likely a preventable death.”.

The panel also cast doubt on the supposed insulin poisonings, which were the foundation of the prosecution case. Jurors in Letby’s original trial were told that the insulin and c-peptide levels of two infants meant they must have been deliberately injected with insulin. Letby’s original legal team did not contest that claim, yet the jury was told that Letby was the only person who could have poisoned both babies.