A review of surgical practices at Our Lady's Hospital in Navan, Co Meath is under way after concerns were raised about the outcome of several operations.
The investigation was prompted by an expert report which conducted a risk review of the general surgical services at the hospital last year.
The Health Service Executive would not confirm reports that some of the cases involved patients who died during their operations.
The report raised concerns about the outcome of several operations and requested a review of some 20 surgical cases.
The report recommended a review be undertaken to assess which procedures are undertaken too infrequently to maintain competence and also to assess the quality of clinical management in a selection of named and random cases.
The HSE said a group of experts from outside the north east has been established to carry out the review.
It also confirmed that several allegations of bullying had been received at the hospital and were being "managed in accordance with due process".