The district health board's chief executive, Dr Dale Bramley, told reporters this afternoon the man entered the country on March 6 and became unwell earlier this week. There is no known community spread, however.
The man was in New Jersey in the United States and flew home via Houston.
Others on the flight should not be alarmed, as the man only developed symptoms early this week.
The man was tested for the virus by his GP in Auckland on Thursday. He is doing "very well" and is at home recovering, Bramley said.
The man attended a service at St Mary's church in East St, Papakura, on Sunday, March 8, at 8.30am.
Health bosses are contacting some people and putting them into monitored self-isolation.
Those who were at the service should contact Healthline 0800 358 5453 or ring ahead to their GP if they become unwell.
The sixth case rang ahead to their GP and alerted them he might be infected and the test was held outside of the centre - which was the correct way to do it, Bramley said.
People in the community are being told not to attend work or where people gather if they are feeling unwell, Bramley reiterated.
Auckland GPs had so far done a great job in their efforts against the coronavirus, Bramley said. If they had concerns, they should contact their local DHB for help.
Gown, gloves and goggles would be worn by GPs when testing people for coronavirus before being thrown out after one use.
