Update - 1.10pm: The Minister for Health, Simon Harris, has criticised the failure of some hospital consultants to comply with their contracts.
Mr Harris called their failure to deliver their work commitment to the public hospital system "brazen, immoral and unfair."
An investigation by RTÉ found that hospital consultants in 14 out of the country's 47 acute public hospitals treated more private patients than they were allowed to under a contract agreed with the HSE.
Minister Harris said: "I can only describe the behaviour highlighted by last night’s RTE Investigates programme, as brazen, immoral and unfair.
"Some consultants behaving this way brings the system into disrepute and lets down a lot of their colleagues, who go above and beyond every day caring for patients and often work well beyond the hours required under their contracts. We cannot have a situation where people are paid for hours and don't do them.
"This would not be tolerated for nurses or other grades in the service."
He revealed that the HSE have this morning decided to launch formal investigations in the wake of last night’s RTE Investigates programme.
Mr Harris said: "It is the responsibility of management to make sure these contracts are being enforced and I have asked the HSE to ensure that more robust measures are in place in 2018 to make sure consultants comply with their contractual obligations. I will require absolute assurances on this point.
"For some time my Department has been working closely with the HSE on this. In fact, several months ago, the Department wrote to the HSE emphasising the need to pursue compliance.
"In the longer term I have established an independent group, chaired by Dr Donal de Buitléir, to examine the impact of separating private practice from the public hospital system. This was one of the key recommendations of the Sláintecare Report.
"I was struck by the personal stories highlighted by RTE last night and the very distressing impact on patients of waiting for procedures, and I would like to assure people that I am committed to improving access for public patients to public hospital care."
Earlier: No one is counting consultants’ hours according to a leading health expert.
The claim follows a Prime Time report claiming some consultants spend more time treating private patients than public ones.
The HSE says many consultants actually work beyond their contracted hours in public hospitals.
But Professor Anthony Staines, from DCU, says there is no one monitoring hours and minutes.
"There is a couple of things happening. One is the hospitals have a big incentive to treat private patients because it is a significant source of funding," said Professor Staines.
"I do know that it is not being effectively managed and recorded."
The Irish Hospital Consultants Association said that it can confidently state that the overwhelming majority of consultants are "working well beyond their contracted hours in an effort to provide care for patients in an under-resourced health care system".