A leading paediatrician has been found guilty of professional misconduct after accusing solicitor Sally Clark's husband of murdering their children.
Sally Clark was cleared of murdering her two sons
The General Medical Council has now ruled the way Professor David Southall works should be restricted.
The expert accused Mr Clark of the murders on the basis of a TV documentary. Mrs Clark was jailed and later cleared of killing the boys.
The family had been calling for the doctor to be struck off by the GMC.
At the GMC hearing in Manchester, tribunal chairman Denis McDevitt told Professor Southall he must not engage in any aspect of child protection work either in or outside the NHS for three years.
Mr McDevitt, chairman of the GMC's professional conduct committee, told Professor Southall his conduct amounted to "a serious departure from the standards expected from a registered medical practitioner."
He added: "The committee are concerned that at no time during these proceedings have you seen fit to withdraw these allegations or to offer any apology."
However, Professor Southall's employers, the University Hospital of North Staffordshire in Stoke, have said the paediatrician will not lose his job.
The GMC is due to hear seven other complaints against Professor Southall at a hearing expected to take place in January.
After the judgement, Steve Clark said: "It is a sad day when a doctor is dragged before his professional body, is found guilty of serious professional misconduct and
has sanctions imposed upon him.
But he added: "As a father, the sole purpose of bringing my complaint, four long years ago, was to try to ensure that no other innocent parent is ever again falsely accused of harming their children.
He said he hoped the committee's verdict would send a strong message to all doctors that such accusations were "not acceptable and will no longer be tolerated".
Mr Clark added: "I am also, of course, relieved that at last my complaints have been upheld and I have been fully exonerated from any blame."
Professor Southall's solicitor, Margaret Taylor, said: "Although disappointed that conditions have been applied to his registration, he sincerely hopes that the decision will not deter other paediatricians from continuing to act in the particularly difficult area of child protection, and speaking out when they believe a child is being abused."
Professor Southall 'abused his position'
The paediatrician has not retracted his allegations.
Mervyn Gamage, a spokesman for the University Hospital of North Staffordshire, said the trust agreed the specialist should have raised his concerns about the Clark case in a different way.
But he praised Professor Southall, adding: "This penalty will allow him to continue to use his clinical skills for the benefit of sick children."
Dr Dominic Croft, a consultant paediatrician, also praised the paediatrician's expertise.
He told the BBC: "I'm very glad, and I'm sure everyone in the profession is glad, that Professor Southall is going to be able to continue to practise medicine."
Penny Mellor, who runs 'Dare to Care', a support group for parents accused of harming their children, said Professor Southall's behaviour had been a striking off offence.
But she said the GMC's decision meant the other complaints against Professor Southall would be considered.
"If he had been struck off, no other complaints could have been heard, so the other complainants could never have had their day in court."
The other cases, which are unconnected to the Clark's complaint, are due to be considered by the GMC in January.
Sally Clark was convicted in 1999 of murdering her two sons Christopher and Harry.
But that conviction was quashed when new medical evidence showing the babies died of natural causes was accepted at a second appeal hearing in January 2003.
The GMC hearing centred around conclusions Professor Southall drew after seeing an interview with Mr Clark on Channel 4's Dispatches programme broadcast in April 2000.
In his interview, Mr Clark described how the couple's first baby Christopher had suffered a nosebleed just 10 days before he died in December 1996.
Professor Southall told police he believed Mr Clark had killed the children after watching the interview, but without seeing any documents relating to the case or interviewing the family.
He later outlined his concerns in a report. It was submitted to the family court, which was considering who should take care of the Clark's third child.