Rotorua firefighters did well to keep a massive fire from spreading to a residential area, the city's deputy mayor says.
Last night's fire gutted St John's Presbyterian Church.
Twelve fire crews, called from all around the district, took more than two hours to bring the blaze under control.
Police are treating the fire as suspicious and want to hear from anyone who saw a person or people near the building before the fire or running away from it soon after.
Rotorua resident Neville Raethel, who was at the scene, said flames quickly engulfed the entire building.
"The flames were probably 40 or 50 feet above where the church bell was and as I got closer I could actually see the big church bell housing that they have there was [alight]."
A creche next door also caught fire, Mr Raethel said.
Rotorua deputy mayor Dave Donaldson visited the site last night and said the fire's intensity was "quite severe."
"There was a high-density residential area immediately downwind of the church, so to contain it just to the site of the church has been a great piece of firefighting."
He refused to speculate on the cause of the fire.
"It's prudent to wait until fire investigators have had a look."
The scene examination may take a number of days and police said with the church so unstable, it was dangerous to be anywhere near it.
Mr Donaldson was to meet Mayor Steve Chadwick and the council's chief executive to see what could be done to help the congregation.
St John's minister Reverend Ed Masters said while the church congregation was deeply upset, he was thankful no one was hurt.