Last month, a fire in the cinema caused minor damage, but early detection by a recently installed fire alarm meant fire crews were there within five minutes.
Central Otago District Mayor Tamah Alley said the talk was that yesterday's fire might also have been caused by an electrical fault.
But fire investigator John Smalls said this morning it was too early to say what may have caused the blaze and he was not willing to speculate.
Mr Smalls said the scene investigation would begin if drone footage showed the site was safe.
Roxburgh residents have gathered in "disbelief" at what once was the town's beloved historic cinema and hall.
An Otago Daily Times reporter at the scene said people had continued to visit at the site in "disbelief", taking photos and sharing memories of the building.
"People are coming back because they can't quite believe it was as bad as it was," she said.
Fire trucks had remained at the site overnight and faint smoke was still rising from the building's remains, she said.
The cinema's facade was still standing, although a fall area had been established in front of it.
The reporter said, aside from blown-out windows, "if you looked down the street, you wouldn't know anything had happened".
However, inside only rubble remained - treasured items like old movie posters, historic projection equipment and a grand piano reduced to ash.
Yesterday, the town hall had been demolished to prevent the fire spreading.
Roxburgh chief fire officer David Welsh said the decision was made yesterday afternoon to push over the remains of the town hall, at the rear of the building, to smother the fire and prevent it spreading to surrounding properties.
Nearby buildings had suffered smoke damage but were otherwise unharmed.
Traffic on State Highway 8 through the town was still being diverted through backstreets.
Cinema committee chairman Curtis Crawford wrote in a tribute that the community had "an old faithful friend".
The complex was "where we celebrated everything, entertained the masses, awarded the volunteers and kids of the community, danced the night away or said goodbye to loved ones and friends".
"It was a tough day and days to come on many levels and one that will be spoken about for many years.
"Many a tear from my awesome group of volunteers, helpers and community has been shed as we come to terms with what we have lost."
