The arrests were carried out by the Marine Department (MD) Region 5 and Kathu Police after complaints from local people that the restaurant encroached on the beach and on public land.
The incomplete restaurant, covering about 900 square metres, is built mainly in timber. But there is also a section with concrete pillars, roof and floor.
A retaining wall made from rock has also been planted in the beach to hold a raised sand walkway. Much of the wooden part of the restaurant is built on rocks at the high tide mark.
The owner of the restaurant was not around when the arrests took place. Officials said he or she would be contacted and would be ordered to remove the structure within 30 days.