"Our team rang the police and attempted to provide first aid to the injured man.
"Thankfully, all our people are safe and support is being provided to those involved."
Police confirmed the man was taken to hospital in a stable condition.
Detective Senior Sergeant said that the man was likely to be discharged later on Thursday afternoon.
"Police are still making a number of extensive inquiries to establish exactly how the man was injured. However, the person is not being forthcoming with information," he said.
The investigation includes looking at whether or not the man was injured where he was found or somewhere else.
Police said they have completed a scene examination. Although the investigation is still in its early stages, authorities wanted to reassure the local community that the incident did not appear to be random.
Second man turns up with gunshot wound
Betty praised staff who were involved in the effort to help the injured man.
"We are extremely proud of our team for their swift response and decisive action.
"Our thoughts go out to the injured man and his whānau. We hope he makes a speedy, full recovery."
About three hours after the Mt Wellington incident, police were notified about a man who turned up at Auckland City Hospital with what was described as a "minor gunshot wound injury" at 11.30pm.
Police said it was still too early to speculate whether that incident was linked to the Mt Wellington incident.
Members of the public are being urged to contact police if they were in the area at the time and saw or heard anything that may help authorities.
• Can you help? Contact Police on 105 or CrimeStoppers anonymous on 0800 555 111