The Attorney General is to review cases in which the controversial paediatrician Professor David Southall gave evidence for the prosecution.
Professor Southall 's work provokes strong views
He has been accused of acting inappropriately and is facing a General Medical Council hearing in November.
Professor Southall is alleged to have kept about 4,450 "special" case files on children which were not stored on the child's proper hospital file.
Some of the cases later involved a criminal prosecution.
In a written ministerial statement to the House of Lords, the Attorney General, Lord Goldsmith, said: "It is said that Professor Southall kept so-called 'special case' files containing original medical records relating to his patients that were not also kept on the child's proper hospital file.
"Concerns have been raised that in some of those cases criminal proceedings may have been taken but the existence of the files not revealed, resulting in their not being disclosed as part of the prosecution process.
"I share those concerns."
Lord Goldsmith added: "What is not clear at this stage is the nature and extent of the failure of disclosure, if such it be.
"I have therefore decided that I will conduct an assessment of the cases where Professor Southall was instructed as a prosecution witness to determine if any 'special case' files existed in any cases involving criminal proceedings.
"Once that assessment has been completed, I will decide what, if any, further review is required."
The review, which will be carried out by the Attorney General and the Crown Prosecution Service, will go back 10 years.
Legal representatives for Professor Southall said the expert would not be making any comment.
Frances Swaine, a solicitor who has represented families who had children taken away from them after Professor Southall gave evidence in their cases, welcomed the Attorney General's investigation.
She said: "It will be a relief to a lot of families."
Ms Swaine said families had told her they believed Professor Southall had kept files on their children.
"It's absolutely crucial to be able to find out what happened to their families. In a great number of cases, their family lives were torn apart."
Professor Southall has had a chequered career.
The High Court decided he should not be struck off the medical register in 2005 after he accused solicitor Sally Clark's husband of murdering their sons - reversing a General Medical Council decision.
But many child health experts praise his research into Munchausen's syndrome by proxy.
This is a condition where adults fabricate or induce illness in their children.
He also pioneered a trial of a CNEP therapy - continuous negative-extrathoracic pressure - where pressure is applied to a premature child's chest to aid breathing.
A spokesman for the Royal College of Paediatrics and Child Health, said: "We regret that it has been thought necessary to undertake this review."