A doctor who accused a father of murdering his two sons after watching a TV documentary made a "quantum leap", a medical tribunal has heard.
Sally Clark was cleared of murdering her two sons
Professor David Southall made the claims about Steve Clark, whose wife Sally was jailed for and then cleared of murdering their baby sons.
But Professor Dennis McDevitt, chairing a General Medical Council hearing, said there was no evidence for his theories.
The GMC is considering whether he should be struck off.
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 case centres around conclusions Prof 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.
ProfessorSouthall told the GMC that he still believed that Mr Clark may have killed the children, and said he stood by his decision to contact the police regarding his theory.
He said his actions had been informed by his experience as a paediatrician.
But Professor McDevitt questioned research carried out by Professor Southall in 1997 into the relationship between children suffering nosebleeds and suffocation attempts.
He suggested the research was based on a very small study "without an
Nobody disputed that Professor Southall should have told the authorities of his concerns that Mr Clark could be the killer, but "everything beyond that seems to be a quantum leap", he added.
"You have had to concoct stories in your own mind to make Mr Clark pivotal to
everything after without, as far as I can understand, any evidence to support
these theories at all."
In his closing speech, Richard Tyson, for the GMC, said: "Professor Southall has not really changed his views at all even with the benefit of hindsight nor has he apologised or expressed any regret over his high handed actions.
"It appears that he remains convinced he was right in just about everything
he said in the course of this saga."
But Professor Southall told the hearing he was concerned that he had given the
chairman of the committee the impression that the conclusions of his research
applied to any baby.
He said: "It was only relevant to the babies in the project."
Kieran Coonan, for Professor Southall, said the paediatrician had been acting in an "anonymous state".
"He was simply acting as a concerned informant at that stage."
He said he was "perfectly entitled" to go to the police on that basis.
"Whether or not you lacked primary data at this stage, the greater your
concern, the stronger your belief is held, the greater the duty to do something
Mr Clark, who lodged a complaint against the professor, told the GMC hearing last week that he had thought the allegations against him were a "sick joke".
Professor Southall, based at North Staffordshire Hospital in Stoke, is one of Britain's leading experts on Munchausen's Syndrome By Proxy, a condition which apparently drives parents to harm their own children in order to win attention.
The case was adjourned until Tuesday.