The New South Wales government has promised to make sure there is no repeat of the “horrible mistake” that saw the wrong side of a patient’s bowel removed at a Sydney hospital.

The error took place at the troubled public-private hospital last week. It’s understood the male patient underwent corrective surgery on Friday.

The state’s health minister, Brad Hazzard, said the hospital had advised NSW Health of the “serious event”.

It has been alleged the patient’s pathology results from a private provider in some way contributed to the mistake.

“In such situations there are investigative processes and those must proceed to their conclusion before any further comment can be made,” Hazzard said on Monday. “The patient’s privacy must also be respected.”

Hazzard has asked the hospital to provide all possible support for the patient and his family.

A spokesman for the 488-bed hospital – which only opened in October – said the cause of the blunder was under investigation.

“The patient and their family have been provided full disclosure and NBH is supporting their ongoing care and treatment,” he said.

NSW premier Gladys Berejiklian said she was very concerned to hear about the incident, which she described as a “horrible, horrible mistake”.

“We need to find out the root cause of the issue and once that’s determined we need to make sure it never happens again,” she told reporters on Monday.

“But our first thought is to make sure the patient is given the best care possible under these terrible circumstances.”