A controversial paediatrician was found guilty of wrongly accusing a grieving mother of drugging and murdering her son. Dr David Southall claimed the mother killed her ten-year-old son after he was found hanged with a belt. He then accused the woman of harming her surviving son and urged social workers to take him into care. The General Medical Council ruled that Southall had "abused" his position and his actions had "added to the distress of a bereaved person". Its fitness to practise panel is yet to decide whether he is guilty of serious professional misconduct, which could lead to him being struck off for life. Southall came to national prominence after accusing solicitor Sally Clark's husband of murdering their children. He called police after seeing Channel 4's Dispatches documentary on the deaths in 2000. Mrs Clark was jailed for the murders, but freed on appeal in 2003. She died in March this year. Southall was found guilty of serious professional misconduct by the GMC in 2004 for his "high-handed intervention" and banned from child protection work for three years. In yesterday's case, a nurse named only as Mrs M was interviewed by Southall in 1998. He accused her of having Munchausen's syndrome by proxy - a parenting disorder first coined by Sir Roy Meadow where the children of sufferers will either have a made-up illness or an induced illness. He suggested she waited until her son was asleep before "wrapping the belt round a curtain pole, lifting him up, buckling the belt around his neck and waiting until he had died". Giving evidence via video link from Australia, where she now lives, Mrs M broke down as she described her interview with Southall in Stroke-on-Trent. "I was just coming to terms with the death of my eldest son and my younger son was taken away from me," she said. She told the panel Southall repeatedly asked how her son, referred to as M1, had died. She said: "I showed him with a pencil and a shoe lace." After her demonstration, Southall looked at her and said "very clever" in a sarcastic tone, Mrs M added. "After all the questions Professor Southall asked me, he said there are only three ways that my son could have possible died, the first being an experiment - I didn't quite know what he meant by that - the second one was that he meant to do it, and the third was that he was murdered.