The Chair of the Oireachtas Health Committee says there is one single public service pay policy, after an audit found senior hospital executives were being paid over €200,000 a year.
The same audit also found some were receiving bonuses and "top ups" from private sources, including a cut from on-campus shops and car parks.
Fine Gael TD and Health Committee Chairman Jerry Buttimer said in these straightened times such payments cannot be condoned.
"This Government and this minister ahs made it quite clear that there is one uniform approach - 'top ups' are a clear breach of policy," he said.
"Any augmentation of payment - be it from a car park or a shop within a hospital is wrong and can't be condoned.
"I'm not going to personalise it in any particular case, but we must be real here."
In one example, the Master of Holles Street is paid a salary of €236,000, but this is "topped up" with private funds of €45,000.
The Tánaiste, Eamon Gilmore, said earlier today that the Government is determined to make sure that public sector pay guidelines are fully complied with.