Letby, who is serving 15 whole-life prison terms, was convicted of murdering seven babies and attempting to murder seven others between June 2015 and June 2016 on the neonatal unit at the Countess of Chester Hospital.

As part of its investigation, the CCRC is likely to consider a major report on the case by an international panel of medical specialists, who presented a summary of their findings this week. The panel was chaired by Dr Shoo Lee, a retired Canadian doctor who specialises in the treatment of young children. It examined 17 cases involved in the Letby trial, and concluded that no murders occurred.

Speaking at a press conference in London this week, Dr Lee said the panel believed that ‘in all cases death or injury were due to natural causes or just bad medical care’. He added: ‘In our opinion, the medical evidence doesn’t support murder in any of these babies.’

During Letby’s trial in 2023, the prosecution referred to an academic paper on air embolism co-authored by Dr Lee. Last July, Letby appealed against her conviction, seeking leave to present as ‘fresh evidence’ two reports by Dr Lee supporting the view that the prosecution experts used his academic paper outside any reliable basis for doing so. However, the appeal was dismissed, at R v Letby [2024] EWCA Crim 748.

A CCRC spokesperson said: ‘We are aware that there has been a great deal of speculation and commentary surrounding Lucy Letby’s case, much of it from parties with only a partial view of the evidence.

‘At this stage it is not possible to determine how long it will take to review this application. A significant volume of complicated evidence was presented to the court in Ms Letby’s trials.’

The CCRC can refer potential miscarriages of justice to the Court of Appeal if new evidence or new argument means there is a real possibility that a conviction will not be upheld, or a sentence will be reduced.