It's harder to imagine feeling a child grow inside you, going through the agonies of labour and then - at a click of a bureaucrat's fingers - seeing your baby snatched away. The expert opinion of Professor Sir Roy Meadow and his disciples had been sought, and they had concluded that the mother was killing her babies.

There was no trial; she didn't have the opportunity to demand that the terrible accusations against her be proved beyond reasonable doubt. Instead, a judge sitting in his chambers decided that, 'on the balance of probabilities', she was a killer. The interests of her surviving children must come first, and they must be taken into care. Unsurprisingly, given the loss of all her children, the mother's mind and marriage fell apart. She and her husband divorced, and he became the obvious candidate to bring up the children.

But there was a catch that the organisers of the Salem witch trials would have applauded. His solicitor, David Sterrett, explained that it wasn't enough for the witch to be condemned without trial. Her husband had to join the denigration of his ex-wife and say that she was a murderer. He didn't believe that for a moment and refused to go along with Meadow. His failure to accept the omniscience of the great man was intolerable. He was deemed unfit to look after his own children and has spent so many years in courts fighting for the right to visit them that his lawyer says he is broke and suffering from 'litigation fatigue'.

The couple might have gone to their local paper for help. They had a sensational story. Their children were to be taken because a professor was claiming the mother was suffering from an exotic condition, Munchausen's syndrome by proxy, which propelled her to kill her children as a means of gaining attention.

Perhaps one reporter in the West Country wouldn't have got very far, but the cumulative effect of reporters on papers around Britain covering the Munchausen mania would have warned the authorities that something akin to a medieval witch craze was sweeping the country. Pressure groups and politicians would have had some hard facts to get their teeth into and the few doctors prepared to break the omertà of the medical profession and dish the dirt on colleagues would have been mobilised.

As it was, Prof Meadow was deferred to for years. The scale of the injustice he contributed to makes the false convictions of the Birmingham Six and Guildford Four look like trivial technical problems. Lord Goldsmith, the Attorney-General, said last week that 258 convictions for murder, infanticide and manslaughter will be reviewed as a matter of urgency.

They are merely an appetiser. Beyond the homicide convictions are the people such as Mr and Mrs A, who have had their children taken into care because they are presumed on the 'balance of probabilities' to be murderers or the aiders and abetters of murder, but have never had the chance to clear their names in court.

Margaret Hodge, the Children's Minister, said that 'thousands or even tens of thousands' of children may have been taken from their parents over the past 15 years because of Meadow's theories. Neither she nor anyone else could be certain because the mass seizure of children took place in camera. There was never a hope of the public being alerted and Meadow being stopped before he caused too much misery. The grotesque snatching of thousands of children was an operation conducted under conditions of the strictest secrecy. Anyone who blew the whistle on the proceedings of the family courts faced prosecution for contempt.

The maxim 'the interests of the child come first' is seductive. Who but a brute could disagree with it? Who would want the interests of the child to come second or third, or not be considered at all? But like many other sweet platitudes, it can lead to monstrous consequences. The supposed interests of the child dictate that mothers can be treated as murderers on 'the balance of probabilities' rather than because they have been found guilty beyond reasonable doubt. If Meadow or one of his clique said that Munchausen's by proxy was probable, then that was enough. The supposed interests of the child also dictated that the courts must destroy families without public scrutiny because publicity would lead to the child being 'stigmatised'.

Yet its clearly not in the interests of the child for the courts to allow him or her to be taken from a loving and innocent mother. The interests being placed first here were the interests of Meadow and Family Court judges who have got away with destroying the lives of largely working-class women for more than a decade, secure in the knowledge that their crackpot theories would never be exposed or tested.

During the years of Meadow's ascendancy, the family courts resembled a secret society. Because there were no outside checks, Munchausen's by proxy became a theory that explained all inexplicable infant deaths. If a baby was fighting fit before dying, then Meadow would say that was proof that a Munchausen mother had smothered the child to attract attention. If a baby was ill before dying, then Meadow would say that was also proof that a Munchausen mother had smothered the child to attract attention.

Munchausen's was an incredible concept in crime fighting: whatever the circumstances, it could damn the guilty woman. It was only when the Court of Appeal spoilt everything by deciding that, while there was no evidence of smothering, there was plenty of evidence that the children were suffering from genetic disorders to such an extent that the universal efficacy of Munchausen's was questioned.

Secrecy allowed incompetence and mania to flourish, as it has done for 20 years. It is not too great an exaggeration to say that families have been forced into a legal world whose practices and assumptions are closer to those of a tyranny than a democracy.

It is a modern phenomenon. In the late 1980s, Iain Walker, a journalist on the Daily Mail, noticed that there was an explosion in the number of injunctions banning inquires about the state's treatment of children. In most cases, no one in his newsroom had the faintest idea who the children were or why the authorities thought reporters might be interested in them. But the injunctions kept dropping out of the fax machine. Disquieted by the assault on freedom of speech, Walker took a sabbatical at Oxford University and published an investigation into the closed world of the Family Courts. As ever, the interests of children came a poor second to the interests in covering up the rank failures of the bureaucracy.

The popularity of gagging orders began after the murder in 1987 of Jasmine Beckford, the Victoria Climbié of her day. Her brutal stepfather was free to kill her in the most revolting manner, even though she was on the at-risk register of Brent council in north London.

The council faced intense media criticism as journalists talked to Jasmine's brothers and sisters about its many failings. The courts agreed to a request from a desperate council that Jasmine's siblings should not be identified, and killed the story.

Brent's success in stopping unwelcome questions encouraged others to go further. Until the exposure of Meadow, the most shocking abuse of state power in family law had been perpetrated by social workers, who had fallen for the theories of American born-again Christians that rings of Satanists routinely abused then ritually sacrificed children in the covens of devil-worshippers. When Rochdale council was caught up in the witch craze, the courts happily granted an injunction that not only prevented the identification of the children involved, but also 'the solicitation or publication of any information about the circumstances of or the reason for those proceedings'.

Nothing could be done to investigate the actions of the social workers, who were eventually proved to be the dupes of hysterics. Even councillors were banned from speaking up for their constituents. As Walker said, Britain was coming perilously close to the 'pre-censorship of totalitarian regimes'.

Margaret Hodge and Helena Kennedy QC are investigating what can be done to clear up the wrecked lives that Meadow has left behind him. A modest first step would be that blundering theorists should not be protected by legal secrecy. If the authorities believe there is evidence to justify taking a child into care, they should present it in open court. If the judge thinks the child should not be named, that would be up to him or her, but the evidence should be tested in public.