The guard, 25-year-old Anuchit Chaitongngam, was found tied up and unconscious in front of Phuket Healthy Nutriment, a tourist attraction on Soi Ta-iad that stages snake shows and sells herbal products. He was taken to Vachira Hospital for treatment.
CCTV footage showed him being attacked by four men wearing masks. After disabling the guard, the four broke into the building and set fire to several parts of it.
The fire caused an estimated B20 million in damage to the welcome area, herb shops and various pieces of furniture.
After interviewing the owner and staff of Phuket Healthy Nutriment, police say they believe a business conflict with a competitor was probably behind the arson attack.
The company has been serving tourists for almost 20 years, attracting more than 500 tourists a day, most of them Chinese.