The blaze was finally extinguished after more than 15 hours

The building, which was under construction to replace the current 110-year-old Maddiston Primary, was due to open to staff and pupils next year.

Fire was discovered in the new school's roof on Wednesday morning.

More than 50 firefighters from Central Scotland Fire and Rescue Service battled to contain the blaze, which was extinguished 15 hours after it started.

An area of the building which was to contain the main entrance, library and gymnasium was worst hit by the fire.

A spokeswoman for Falkirk Council said the current Maddiston Primary, which was closed on Wednesday as a result of the fire, has now reopened.

Building contractor

Education officials have been visiting the site to determine the extent of the damage.

Detective Inspector Wilson Gill, of Central Scotland Police, said a forensic search of the site would now take place.

He said: "At the moment it is unclear why the school was on fire.

"We will be taking a multi-agency approach, involving forensic teams, fire experts and police to find out the root cause.

"At the moment there is nothing to suggest it was malicious.

"However, I want to emphasise that we are not discounting the possibility it may have been started deliberately."

Council officials plan to meet with the school's building contractor, Graham Construction, to assess the future of the building.