Police believe a "suspicious" fire that broke out at an abandoned building in Penzance was started deliberately and is being treated as arson.
Officers were called at 7.25pm by the fire service who were dealing with a small fire on the first floor of a former bakery at Causeway Head on Thursday 5 October.
The building sustained extensive smoke damage but was empty at the time. No one is thought to have been injured.
It is believed that the fire had been smouldering for a few hours before the fire service was alerted.
A Cornwall Fire Service statement said: "Appliances from Penzance, St Just, and St Ives are in attendance at this incident.
"Firefighters wearing breathing apparatus sets are using hose reel jets to extinguish the fire."
Devon and Cornwall Police are asking anyone who saw or heard anything suspicious in the area at the time to contact them online or by telephone on 101, quoting crime reference 50230267420.