''We are treating this as a suspicious incident,'' said police Inspector Bruce Middlemiss, who added that a number of people were known to be in the area at the time the fire started.
Chris Levett, the chairman of Cutty Sark Enterprises, said half of the ship's planking and many historic artifacts had been taken away during the restoration work. He expressed confidence that the vessel could be restored.
''It will be the old ship. The ship has been through many things in its lifetime,'' Levett told BBC radio.
''This is going to make us even more determined to get this ship back up and running and keep her as original as possible,'' Levett said.