A doctor closely associated with Lucy Letby, the nurse convicted of murdering seven infants and attempting to kill seven more at the Countess of Chester Hospital, has died. The registrar, who was in his 50s and had previously worked alongside Letby in 2016, passed away last month after a period of illness. His funeral has already taken place.

During Letby’s trial, which lasted ten months, the doctor was granted anonymity and was referred to as Doctor A in court to protect his family. Prosecutors described him as Letby’s “boyfriend” and suggested that she was infatuated with him, alleging she created dangerous situations by harming babies to prompt him to attend emergencies. Evidence presented at trial included more than 1,300 Facebook messages exchanged between the two over a period of three months in 2016.

Letby herself denied having a romantic relationship with the doctor, asserting they were trusted friends. However, some of their correspondence included affectionate terms such as “sweetie,” and she reportedly became emotional when he entered the dock at Manchester Crown Court. The court also heard that the doctor once expressed significant trust in Letby, stating she was "one of the few nurses I would trust with my own children."

At the 2024 Thirlwall Inquiry, the doctor testified that he had been “misled” and “maybe manipulated” by Letby, acknowledging that she had tricked him into providing information about babies she had harmed.

Letby is currently serving a whole-life order at Bronzefield Prison in Surrey. Despite her conviction, she continues to maintain her innocence. The Criminal Cases Review Commission is reviewing new evidence submitted by a panel of medical experts who argue that the infants’ deaths may have been caused by natural factors or substandard care rather than deliberate harm. The investigation into these claims remains ongoing.