Dr Stephen Bolsin, former consultant anaesthetist at the hospital, is travelling from Australia to give evidence at the pounds 15m inquiry. He emigrated after allegedly being "frozen out" by the British medical establishment.
Because of his "insider" knowledge, Dr Bolsin is expected to be the star witness among the scores that have already appeared before the inquiry and is expected to be on the stand for four days.
Dr Bolsin has been hailed as a hero for exposing the high death rate in children having heart surgery at the infirmary in the early Nineties. Dr Bolsin, who is now director of anaesthesia at the Geelong hospital in Victoria, is described as a man of courage who put his principles before his career when he saw children "dying needlessly" in the infirmary's paediatric unit. Once his suspicions were raised he did an audit of the unit and presented the figures to the hospital's management to prove his case.
His action ultimately led to findings of serious professional misconduct against two former surgeons and the former chief executive after the longest hearing of the General Medical Council on record.
The public inquiry, which is chaired by Professor Ian Kennedy, was launched in October 1998 and it is expected to report late next year.
It is anticipated that it will ex-amine aspects of Dr Bolsin's audit, including its timing and his reasons for carrying it out. While the surgeons, James Wisheart and Janardan Dhasmana, were held directly responsible for the high infant mortality rate, the role played by cardiologists, anaesthetists and paediatricians will also be scrutinised.
Why the problems in the paediatric unit were allowed to continue for as long as they did will also be investigated.
Dr Bolsin has described how he suffered for his intervention, with threats to his career, being ostracised by colleagues and being prevented from doing private work.