File on 4 examines some of the most contentious statistical, scientific and medical evidence in the Lucy Letby trial. The programme reveals new concerns involving medical evidence presented in court where Letby was convicted of murdering seven babies and attempting to murder seven others.

Reporter: Stephanie Hegarty

Producers: Fay Nurse, Ben Robinson and Hayley MortimerTechnical Producers: Richard Hannaford and Nicky EdwardsProduction Coordinator: Tim FernleyEditor: Carl Johnston