Police are investigating a fire that extensively damaged an adult book shop in St Marys on Sunday, August 31.
Police said Fire and Rescue NSW were called to a business on Station Street following reports of a fire at about 8pm.
At the scene they found smoke and flames coming from the book shop on the second floor of the building.
Fire-fighters managed to contain and extinguish the blaze, however, the second floor of the building sustained extensive damage.
No one was injured during the fire.
A crime scene was established and the building was examined by fire investigation officers on Monday, September 1.
The cause of the fire is unknown.
Police are urging anyone with information about this incident to call Crime Stoppers on 1800th333th 000.