A group of seven leading experts has raised concerns regarding the evidence used in the conviction of Lucy Letby, a former nurse convicted of poisoning infants.

Their findings are presented in an 86-page report submitted to the Criminal Cases Review Commission (CCRC).

Letby, 35, was found guilty of deliberately administering insulin to two baby boys at the Countess of Chester hospital, with the incidents occurring in August 2015 and April 2016. The prosecution asserted there was 'no doubt' about the nature of the events and emphasized that these were intentional acts rather than accidents based on the infants' blood glucose levels.

The cases involving the two infants are deemed critical, as they formed the backbone of the prosecution’s argument.

The trial judge, Mr Justice Goss, advised jurors that certainty regarding the two incidents could influence their decisions on other related charges.

However, Letby’s legal representatives claim that jurors were misled about specific details concerning these insulin cases.

The newly submitted report states that the Roche immunoassay test, which provided evidence of deliberate poisoning, might not be reliable.

Letby’s legal team consists of experts in fields such as immunoassays and paediatric endocrinology.

In conjunction with this report, Letby’s barrister, Mark McDonald, will submit another extensive report comprising 698 pages authored by 14 additional experts.

This document reportedly finds no evidence of deliberate harm against Letby.

McDonald has stated that the fresh evidence undermines the prosecution's case and suggests that the review represents the broadest international assessment of neonatal medicine to date, which calls the safety of Letby’s convictions into question.

He emphasized the need for urgent action from the CCRC, suggesting that the findings warrant reopening the case for appeals.

Currently, Letby is serving 15 life sentences for her convictions, which include the murder of seven infants and attempts to kill another seven.

The CCRC began reviewing the case earlier this year following a summary report provided by Letby’s legal team.

However, the organization clarified that the timeline for deciding whether to refer the case back to the court of appeal remains uncertain, particularly given the case's complexity and the extensive evidence evaluated during Letby’s two trials, which lasted over 11 months.

Legal representatives for the families of the affected infants have expressed unwavering confidence in the convictions and criticized the narrative offered by Letby's supporters as lacking robust evidence and being overly sensationalized.

During the Thirlwall inquiry into the deaths, a barrister representing the families described earlier presented materials as outdated and flawed in their analysis.

Separately, Cheshire Constabulary is conducting an investigation into whether Letby mismanaged other infants at both the Countess of Chester hospital and Liverpool Women’s hospital between 2012 and 2016. The police force is also exploring allegations of gross negligence manslaughter by other hospital staff, alongside potential corporate manslaughter charges against the Countess of Chester hospital.

In response to criticisms of its investigation, the Cheshire Constabulary reported that the critiques were based on limited knowledge and asserted that their inquiry had been conducted with significant detail and diligence.