The General Medical Council today won its appeal over a high court ruling that expert witnesses such as the paediatrician Sir Roy Meadow are immune from disciplinary action.

Sir Roy was struck off by the GMC, the doctors' regulatory body, after giving misleading statistical evidence that helped convict Sally Clark of murdering her two children.

A judge at the high court in London ruled that all expert witnesses should be immune from disciplinary action. The judge said Sir Roy was not guilty of serious professional misconduct and his striking off should be quashed.

Today, the court of appeal today overturned the ruling on immunity for expert witness, but dismissed the GMC's challenge to the finding that Sir Roy had not been guilty of serious professional misconduct.

The GMC did not seek to reinstate the striking off of the 73-year-old, who has retired from the medical profession.

"I am glad that the court of appeal has agreed with the previous high court judgment that my evidence in the trial of Ms Clark ... was not an example of serious professional misconduct, and that the GMC was wrong in its judgment of me," Sir Roy, who was in court to hear the ruling, said.

Finlay Scott, the chief executive of the GMC, welcomed the decision on the power of regulators. "We are very pleased with today's decision that there is no immunity from action by the GMC and other regulators," he said.

"The court of appeal has upheld our view that the GMC is free to act to protect the public when a doctor has fallen significantly below acceptable standards. This is a very important point of law."

He said the GMC had "consistently recognised that it cannot be in the public interest if doctors are deterred from giving evidence, honestly and truthfully, and within their competence".

However, he added that the regulatory body "did not believe that the solution lay in extending the principle of immunity in a way that placed doctors and other professionals beyond the reach of their regulator" and said it was "very pleased" that the court had agreed.

Sir Roy was acclaimed as an expert in the field of Sudden Infant Death Syndrome and how such deaths could be differentiated from children harmed by their parents - so-called Munchausen's Syndrome by Proxy.

He gave evidence that the risk of two infants dying naturally of Sids in a household such as Ms Clark's was effectively one in 73m.

He also gave evidence in the child murder trials of Angela Cannings and Donna Anthony, who were jailed for murdering their children but were later cleared by the court of appeal.