Hospital chiefs are expected to be called before the Dail Public Accounts Committee to shed light on the payment of top-up money to senior managers' salaries, mostly from from private sources.

The Committee is likely to hold special hearings to investigate the issue after it emerged that the Masters of Holles Street and the Rotunda maternity hospitals and senior staff in these and other hospitals and health agencies were having their public salaries topped up by extra payments, in contravention of Government pay policy.

Both Taoiseach Enda Kenny and Health Minister James Reilly have said the top-up pay practice must end.

However, the Irish Times reports today that in late 2011,some months after Dr Reilly became Minister, the Department of Health got approval from the Department of Public Expenditure and Reform to pay a salary of up to €195,000 to Bill Maher, the then acting chief executive of St Vincent's Hospital in Dublin, whose pay rate was then €146,000, to take over the running of a newly-formed hospitals group in the West of Ireland.

Some months later Minister Reilly ordered an internal HSE audit that has recently revealed the widespread top-up payments to health chiefs. He ordered this probe after the health safety body HIQA in the summer of 2012 made reference to substantial top up payments for senior managers at Tallaght Hospital.

irishhealth.com revealed earlier this year that a probe into the Tallaght payments said it could find no documentary evidence to explain the rationale or approval process for the hospital setting up a fund which paid out around €700,000 in 'top-up' earnings to five senior staff between 2005 and 2010.

Tallaght Hospital has said these extra payments, which were made from HSE funding, ceased in 2010. However, it has now emerged that a number of other hospitals and health agencies have continued the top-up pay practice.

The Department of Health has said the higher salary approval for Mr Maher in 2011 was an exceptional matter and did not represent a change in overall public service pay policy. The salary level approved in this case is similar to the level approved by the Government for the Director General of the HSE.

Top-up payments revealed to date in the HSE's audit include an extra €20,000 to Rotunda Master Dr Sam Coulter Smith and an extra €45,000 to Holles Street Master Dr Rhona Mahony. Top-up pay to managers at other hospitals, including our Lady's in Crumlin and the Mater, have also been revealed.

Fianna Fáil Spokesperson on Public Expenditure Seán Fleming said that the Government has known since last March about top-ups for hospital bosses.

Deputy Fleming said the HSE internal audit, commissioned by the Minister for Health James Reilly, which covers the salaries and top ups of all senior hospital executives across the country was finalised on March 15 of this year.

"The evidence shows that the Government has turned a blind eye to this since it received the audit eight months ago. All the while, the same Government was engaged in a slash and burn of small, basic allowances for lower paid health workers," Deputy Fleming said.