A bombshell statement given to police that supported Lucy Letby's claim to be innocent of murdering babies was not disclosed to her defence team, it was claimed yesterday.

The evidence from Dr Astha Soni, a paediatrician at the neonatal unit at the Countess of Chester Hospital where Letby worked, disputed claims by prosecution experts that the poor health of one baby in the unit, Baby Y, was linked to insulin poisoning by Letby.

The nurse, now 35, was never accused of trying to harm him, but was convicted of the attempted murder of two other babies through insulin poisoning.

According to the UnHerd website, Dr Soni's statement said Baby Y's high insulin levels were due to a genetic condition which produces excess levels of the hormone.

This contradicted claims by Dewi Evans, the controversial retired paediatrician who played a central role in the prosecution, who told police that Baby Y had been given 'insulin from an external source'.

The statement by Dr Soni calls into question the prosecution's methodology and was never passed to Letby's defence by the Crown Prosecution Service (CPS).

Mysteriously, Dr Soni's document briefly appeared on the website of Lady Justice Thirwall's public inquiry into the Letby case late on February 17 before vanishing soon afterwards. 

The growing doubts about the safety of Letby's conviction are placing pressure on Lady Thirwall to pause her inquiry, which is based on the presumption Letby is guilty.

British-based neonatologists Svilena Dimitrova and Neil Aiton have compiled reports on three of the deaths that challenge evidence given at Letby's 2023 trial, while a separate panel of experts concluded last month there was 'no medical evidence to support malfeasance'. 

The specialists believe the babies died from 'either natural causes or bad medical care'.

Lord [Ken] Macdonald KC, a former head of the CPS, told UnHerd that Dr Soni's statement appeared to meet the legal test for discloure to Letby's lawyers before the trial, which is that it was 'capable either of undermining the prosecution case or assisting the defence'.

UnHerd also reveals that neither of the juries in Letby's two trials were told a dangerous respiratory virus was ravaging the neo-natal ward just before one baby's death.

The CPS declined to comment, other than to stress that she had been found guilty.