Former IBEC Director General Turlough O'Sullivan will investigate whether HSE staff complied with regulations relating to the controversial Skill training programme.
It was a HSE internal audit that uncovered that the €2.35m training fund was used to pay for 31 foreign trips.
Mr O'Sullivan will look into issues such as spouses travelling on official trips abroad.
The fund has become the subject of a formal garda investigation.
HSE Chief Executive Professor Brendan Drumm said the money had been 'channelled' from the Department of Health to SIPTU via the HSE since 2002 in sums averaging 250,000 a year.
SIPTU has denied that the money was paid into any account under its control, but a union official is under internal investigation.
Five bodies are now investigating the operation of the fund, including gardaí, the Comptroller and Auditor General, the Departments of Health and Finance, and SIPTU.
It has emerged tonight that an internal audit of the programme found a staff member had been recruited inappropriately, while another received inappropriate pension arrangements.
The investigation is due to take eight weeks and the HSE has said it will publish its findings in full.
