Staff are putting on the finishing touches after the business was forced to close five weeks ago.
Police said initial indications suggest there are serious injuries.
A helicopter with night vision equipment was deployed to search for him after he was reported missing, but with no success.
An image supplied to Newshub showed multiple police cars outside.
A drone flew over the area overnight.
It's been exactly a week since the Port Hills lit up in flames.
Many are volunteers from around the country, who have jobs that have taken a back seat.
The 650-hectare blaze broke out on the hills last week and crews have been working to get it under control ever since.
The fire, near Waipara, jumped its containment line on Monday afternoon.