Police have launched an investigation after a fire took hold at the former Strathmartine Hospital last night.
Firefighters were called to a blaze in a derelict building at 8.05pm and took over two hours to extinguish the flames.
A spokesman for Scottish Fire and Rescue Service said four appliances had been involved, using aerial equipment and two main jets.
Crews stood down at 10.37pm.
Officers have already spoken to a number of witnesses and are following a line of inquiry, but would still like to speak with anyone who has relevant information that could assist their investigation.
A statement released on Police Scotland’s Facebook page read: “This is one of a number of empty and derelict buildings in Tayside, many of which are hazardous environments.
“People place themselves at risk if they enter these buildings, climb on scaffolding or on the roofs, and especially if they are reckless enough to start fires.
“They are boarded up for a reason and are potentially unsafe, may possibly contain hazardous materials such as asbestos, or be structurally unsound.”
Last week campaigner Karen McCauley called for action to seal the former orphanage and psychiatric hospital after recent pictures showed the dilapidated buildings could be easily accessed.
She feared the grounds could become a magnet for bored teenagers during lockdown.
On social media people reported seeing youths near the grounds last night.
A spokesman for Police Scotland said officers were called to the fire at 8.10pm.
She added: “A joint investigation is to be carried out with Scottish Fire and Rescue Service.”