A paediatrician urged social services to take a boy into care right away, the General Medical Council (GMC) heard.
David Southall denies serious professional misconduct
Professor David Southall said he believed the child, known as M2 at the disciplinary hearing, was "at serious risk" from his mother, known as Mrs M.
The GMC is investigating claims the professor acted inappropriately.
In 2004 he was found guilty of serious professional misconduct for accusing solicitor Sally Clark's husband of murdering their children.
Prof Southall is facing a number of charges in relation to six different children in the 1980s and 1990s.
He has been accused of abusing his professional position, acting inappropriately and adding to Mrs M's distress when he interviewed her about the death of her other son, known as M1.
Prof Southall, who worked at London's Royal Brompton Hospital before moving to the North Staffordshire hospital, denies serious professional misconduct.
The GMC fitness to practise panel heard that a social worker, Francine Salem, contacted Prof Southall in January 1998 to ask his opinion on the case.
The panel has previously heard how M2's brother, M1, died in June 1996 after he was found hanging with a belt around his neck from a curtain pole in the family home.
Some time after M1's death, social services had been alerted to concerns about M2 who was apparently displaying suicidal tendencies.
Miss Salem said she had contacted Prof Southall and had given him background details of the case.
On Thursday she told the panel: "He shared my anxieties and felt I was right in suspecting that this may be a case of parental-induced illness.
"He believed we had a major protection issue here and suggested we needed him on board."
When asked by Prof Southall's QC Kieran Coonan why she had contacted Dr Southall specifically, Miss Salem replied: "Obviously because of his knowledge in the area of parental-induced illness which was one of the hypotheses we were looking at at the time."
The panel heard that on 28 January 1998, Miss Salem and her superior visited Prof Southall at his offices.
A note of the visit said: "Having considered all the information available he (Prof Southall) is still of the opinion that the mother has Munchausen's Syndrome and this will lead to M2 being at serious risk from her.
"He advised we should remove M2 at once and have him medically examined and memorandum interviewed."
An Emergency Protection Order (EPO) to take M2 from the family home was granted by magistrates the following day, the panel was told.
The hearing continues.