The Irish Medical Council has begun an inquiry into the conduct of the former chief medical officer of the Blood Transfusion Service, Dr Terry Walsh, according to RTÉ.
The station reported that the investigation started over two months ago and related to the infection of people with hepatitis C through blood and blood products.
The chairman of the Irish Medical Council, Prof Gerard Bury, last night declined to comment "in any way, shape or form" about the matter.
This is understood to be the first time that any person has faced an assessment of their professional conduct during the catastrophic period for the transfusion service, which was previously known as the Blood Transfusion Service Board.
The former chief medical officer is expected to defend himself vigorously against any allegation of misconduct, should the issue go to a full hearing.
Dr Walsh joined the Blood Bank in 1969 and became chief medical officer fewer than 20 years later.
He retired in 1995 on full pension.
He has given evidence at two inquiries into the blood supply.
The Lindsay Tribunal into the infection of people with haemophilia concluded recently.
The Finlay Tribunal investigated how hepatitis C contaminated the anti-D blood product made at the old Blood Bank headquarters.