An unnamed hospital consultant, whose basic salary is €155,000 a year, was paid €736,000 for public work last year, the Public Accounts Committee has heard.
On top of the basic €155,000, the consultant received €334,215 in on-call payments, mostly for emergency work, plus €246,774 for planned work, mainly to keep colonoscopy waiting lists down.
The Health Service Executive told the Committee that there were truly exceptional circumstances to the case.
There had been a team of four surgeons at the hospital but the consultant ended up covering the team alone last year.
This meant the doctor was the sole consultant surgeon on-call, in a hospital that has a 24/7 emergency department.
He was also needed to keep planned colonoscopy procedures within the four-week waiting period.
The issue was raised by PAC chairman, John McGuinness who asked if the surgeon "ever went to bed".
Stephen Mulvany, chief financial officer of the HSE said the situation had normalised this year with an increased surgical team at the hospital.