Professor Southall is unrepentant over his methods
David Southall is, depending on the point of view, either one of Britain's most hated and dangerous doctors - or one of its most dedicated protectors of vulnerable children.
The paediatrician best known for accusing a man of killing his children after seeing him interviewed in a television documentary, David Southall says he has no regrets and that the hate campaign against him is the price he is paying for observing his duty to protect children.
In "A Very Dangerous Doctor", Panorama gains exclusive access to Professor Southall at a time when child protection is very much back in the spotlight and his career as a top consultant hanging in the balance.
On 22 May, a High Court judge upheld the decision by the General Medical Council to strike Dr Southall off the medical register for serious professional misconduct, a decision the medical journal The Lancet described as "incomprehensible".
But the Panorama team challenges some of the long held views about the doctor who has been labelled "a monster".
In revisiting the complex chain of events that have sent his case to the country's highest courts, Professor Southall tells Panorama reporter Vivian White that he has done nothing wrong.
"I was probably the preeminent expert on intentional suffocation in the world at that time," Dr Southall said of the role he took upon himself in one of Britain's highest profile child death cases.
Going back more than 20 years, Dr Southall, who specialised in infants with breathing difficulties, began to suspect that some of the children he was seeing with unexplained symptoms had been intentionally suffocated. He obtained permission to begin secretly filming, in hospital, parents who were already suspected of abuse with their children.
First at the Royal Brompton Hospital in London and, later, at the North Staffordshire Hospital in Stoke, he uncovered a series of incidences of child abuse and he became an expert in Munchausen's Syndrome by Proxy, also known as Fabricated or Induced Illness.
Adults with the condition may induce or exaggerate illness in children to attract attention to themselves.
Some of the secret filming led to child care proceedings and prosecutions. Within the medical profession, it was very controversial.
Mandy Morris told the GMC that Southall accused her of killing her son
Others who came into contact with Dr Southall - or whose own doctors relied on his published research papers - persistently claimed that they were falsely accused of abuses that they did not commit because of his diagnosis or his expert advice.
Their anger, as Vivian White discovers, is palpable.
"That's one doctor that shouldn't be practising medicine as far as I'm concerned," parent Sharon Payne, who was not a patient of Dr Southall, tells Vivian.
Mrs Payne was separated from her child for 12 weeks because of suspicions raised by another doctor whom she believes had been influenced by Dr Southall's research work.
Along with other parents, she became part of a powerful and determined campaign group.
The Panorama team looks at the campaign against Dr Southall and examines some of the tactics used, including accusing the doctor of killing babies during a clinical experiment and bombarding his NHS employers with complaints in a bid to drive him out of the job.
The campaigners helped to ensure that theirs were among more than 40 complaints that were filed with the GMC.
In 2006, it acted on one of those complaints. This time the charge was he had accused a woman, Mandy Morris, whose 10-year-old son had died by hanging, of murdering the boy.
He was struck off as a result.
Panorama also looks back to April 2000 and Dr Southall's intervention in the case of Sally Clark, the mother convicted in 1999 of killing her two infant sons in 1996 and 1998 - a conviction that was overturned on appeal in 2003.
Stephen Clark complained about Southall's intervention in the case
He watched a television documentary on the case featuring Sally Clark's husband, Stephen, describing an incident when he was alone with one of his children. Dr Southall became concerned that Mr Clark was responsible for suffocating his sons.
Mr Clark has never been implicated in the deaths and Dr Southall's action prompted him to also complain to the GMC, which held a hearing in 2004 charging him with serious professional misconduct.
A doctor called as an expert witness was himself personally involved in the case and had previously criticised Dr Southall's work, prompting at least one former member of the GMC to question the entire case against him.
"I don't think he is perfect, who is? But I think that it has been a travesty of justice what has happened to him in these cases that have gone to the GMC," Dr Wendy Savage tells Panorama.
Dr Savage complained to the GMC about the hearing, but it responded that it had sought legal advice and was confident that there was no conflict of interest in relying on the opinions of the doctor with a personal history in the Clark case.
The GMC has told Panorama that all of its dealings with David Southall have been fair and properly conducted and that its most recent finding had been upheld by a higher court. It also disputes claims that its handling of the Southall cases has in any way deterred doctors from entering the field of child protection or reporting evidence of abuse.
Mrs Clark's convictions were overturned on appeal in 2003 and she was released. She died in 2007 at the age of 42, her family said she never recovered from the original miscarriage of justice.
"Nowhere on my list of choices was 'do nothing'," Dr Southall tells Panorama of his decision to act on his suspicions around Stephen Clark. "I didn't make it public, I went through a confidential route, namely the Child Protection Division of the police."
Despite the criticism levelled at the doctor who dared to raise a concern that amounted to an accusation of murder initially based on just a television clip, Dr Southall does have his supporters.
Dr Wendy Savage called Dr Southall's treatment a 'travesty'
Colleagues who work in child protection emphasised that he had a professional duty to intervene.
The GMC's Deputy Chief Executive, Paul Philip, speaking after the High Court decision, said: "The vast majority of doctors in this country do an excellent job often under difficult circumstances, this includes paediatricians engaged in essential child protection work.
"But where our standards have not been met we must and we will act to protect patients and to protect the public interest."
Despite all the questions raised about him, Dr Southall, who admits that he is at times awkward and obstinate, remains unapologetic and plans to fight on in his battle to regain his professional status.
Panorama: "A Very Dangerous Doctor", Monday, 1 June, BBC One at 8.30 pm.