Historic archives are feared lost after a suspicious blaze gutted a 250-year-old lodge.
The fire is believed to have been started deliberately
Moray Council officers believe old letters, pictures and other items may have been damaged in the fire which spread up through Grant Lodge in Elgin early on Saturday.
Built in 1750 for the Seafield family, the lodge had been used to house extensive archive material about the town's history.
Assistant divisional officer Frank Clayton of Grampian Police said he believed the fire may have been deliberately started in the basement some time before 0400 BST.
The fire rose up through the ground, first and second floors, before finally being extinguished at around 0700 BST, he said.
Three fire units and six fire fighters wearing breathing apparatus tackled the blaze.
Building control officers from Moray Council have declared the structure unsafe meaning a full assessment of any damage to archives will take some time.
Council services officer Dougie McPhee said: "The fire was contained within a vertical area, but it has caused severe heat and smoke damage, as well as that caused by the water involved in putting it out.
"The floors and ceilings have also been severely damaged and we can't enter the building until the structural engineers, police and fire brigade have finished their work and it's been made safe."
He added: "Obviously we're concerned about what damage will have been caused to the
archive material, some of which dates back a couple of hundred years, maybe more, and is of importance to the local area."
The lodge was the site of the last clan uprising in Scotland when, in 1820, around 700 highlanders of Clan Grant marched on the lodge to protect Lady Ann Grant during an election dispute.
The property served as Elgin's library for most of the 20th century before housing the local heritage service in 1996.
It had been gifted to the people of Elgin, along with Cooper Park where it is situated, by Sir George Cooper in 1903.
A report on the blaze is being sent to the procurator fiscal and anyone with information on the incident is asked to contact police.