Police are investigating concerns a doctor who saw patients used fake documentation to get a job at Middlemore Hospital.
Te Whatu Ora Counties Manukau said a complaint was filed with police about the man who was employed in a clinical research position in February 2022.
The complaint was regarding documentation that was not authentic.
It said the person no longer worked there.
Te Whatu Ora Health New Zealand said it supported the police referral.
Police refused to comment while the investigation was in its early stages.
Health Minister Andrew Little was made aware on Wednesday.
"I was advised yesterday that a staff member at Middlemore Hospital was stood down last week following concerns raised about his qualifications. I have been advised that an investigation is under way into the actions of this person. I am satisfied at the response of Te Whatu Ora Health NZ to this employment matter," Little said in a statement.
Every patient who saw the man was being contacted and their situation reviewed to ensure they did not have any negative outcomes from their dealings with the man.
Little said the hospital was also reviewing its vetting processes.
He said he would expect the most robust vetting processes to be in place when people were being recruited into the health system.