A cot death expert has expressed his sorrow over the use of figures which led to Sally Clark being wrongly convicted for murdering two children.
Sir Roy was speaking during his GMC hearing
Professor Sir Roy Meadow said his estimate of the likelihood of two cot deaths in her family used at her 1999 trial "misled and confused" people.
He denies charges of serious professional misconduct at the General Medical Council hearing.
Mrs Clark was cleared in 2003 of killing her sons Harry and Christopher.
Sally Clark: Served three years after being wrongly convicted of killing her two sons
Angela Cannings: Served 18 months after being wrongly convicted of killing her two sons
Donna Anthony: Served six years after being wrongly convicted of killing her son and daughter
Trupti Patel: Cleared of killing three of her children
During the GMC hearing, Robert Seabrook QC, acting for the GMC, asked Sir Roy if the way people had been misled about his evidence was something he was "profoundly sorry" about.
He replied: "Yes it is."
Sir Roy had estimated the chance of a double cot death in Sally Clark's family was one in 73 million.
He told the hearing: "I think it's self-evident it misled and confused a lot of people."
He said he was very sorry about it.
Sir Roy said he had not spoken sooner about his regrets because of legal advice and professional etiquette.
He said: "It's been very, very difficult in keeping silent."
Sally Clark's father, Frank Lockyer, who brought the case against the paediatrician, said Sir Roy's comments were a "a significant development".
'Ball park figure'
Sir Roy had earlier told the GMC that at a committal hearing for Mrs Clark, he was asked by defence counsel about the one in 1,000 figure for sudden infant death syndrome.
He said he did not remember where the figure had come from, but when it appeared in an article he had written in an eminent paediatric journal, no one had questioned it.
Sir Roy said it was a "reasonable ball park figure" for the incidence of sudden infant death syndrome for the population as a whole.
He said he had squared it to reach a figure of one child per million for two such deaths in the same family
He then calculated that because of Sally Clark's age and the family's relative affluence, the likelihood in their case was one in 73 million - the figure he used during her trial.
It was later disputed by the Royal Statistical Society and other experts have said that once genetic and environmental factors are taken into consideration, the odds are closer to 200 to one.
Sir Roy had said he had taken the one in 73 million figure to be a "mean figure and there would be a degree of variation on either side".
Last week he told the GMC he did not see himself as an expert statistician.
Sir Roy also gave evidence as an expert witness in the trials of two other women, Angela Cannings and Donna Anthony, who were both freed on appeal after being convicted of murdering their children.
He told the GMC he had concerns over the evidence he saw regarding both Harry and Christopher's deaths.