Exclusive: Jury was never told about inquiry into key prosecution witness Peter Hindmarsh, which looked into allegations including of harm to patients

A doctor who gave crucial expert evidence about insulin poisoning for the prosecution of the nurse Lucy Letby was under investigation by the medical regulator at the time due to serious concerns about his fitness to practise.

The General Medical Council (GMC) opened an investigation into concerns about Prof Peter Hindmarsh, including that he had harmed patients, on the first day he gave evidence at Letby’s trial in late 2022.