A key medical witness in the Lucy Letby trial has said he has changed his mind about how one of the babies was killed.

Lucy Letby was not present when a baby she was convicted of killing was harmed, a BBC investigation has reported. Letby was found guilty of killing a boy known as Baby C by injecting air into his system at the Countess of Chester Hospital in June 2016.

Doctors were growing increasingly concerned about the link between Letby and dying babies at the hospital, but thought the problem would be dealt with by NHS bosses

A doctor has told the public inquiry into Lucy Letby’s crimes that he felt "ashamed" for "failing to protect" babies from the former nurse. Consultant paediatrician Dr John Gibbs, now retired, was working at the Countess of Chester Hospital when Letby began attacking vulnerable babies on the neonatal unit in June 2015.

Letby was convicted of killing the baby just four days after its birth by injecting the baby with air. Dr Gibbs said he was called to the neonatal unit at the Countess of Chester in the evening, at which point Baby C had already collapsed and staff were attempting resuscitation.

Numerous experts have now raised doubts about Letby's conviction, but the growing debate is causing great distress to the families of the victims.