Nimit Sangkajit, Chief of the Phuket Office of the DBD, told The Phuket News that a team would be on the island from February 18 to 22.
Mr Nimit said there were 3,700 foreign-run businesses in Phuket registered with the department, but many of them had illegal Thai shareholders.
Thai people listed as shareholders might be required to show they genuinely had enough money to have been able to have invested in the company, if officials came to check them out.
“The department in Bangkok has checked the data for these companies, and will check each company to ensure the Thai shareholders are genuinely involved,” Mr Nimit said.
“If the business is found to have an illegal Thai shareholder, by law both the Thai shareholder and the foreign operator face a maximum three years in jail, or fined between B100,000 and B1 million.
“They will also be required to stop their business, but if they continue, they will be fined B10,000 to B50,000 per day.”
He revealed that the largest number of foreign businesses in Phuket were British, with 608 registered, following by French, 306, Australian, 244, American, 230, and Italian, 200.
Russians, currently a hot topic following last week’s “anti-Russian” protest in Bang Tao, have 153 businesses in Phuket.
Meanwhile, Yaowapa Piboonpol, chief of the Phuket Provincial Employment Office told The Phuket News there were 8,635 foreigners holding a work permit in Phuket.
Of the island’s three districts, 4777 foreigners are listed in Muang Phuket, 2642 in Kathu, and 1216 in Thalang.
Most work permit holders were British, with 1,169 people, followed by Filipinos (668), Russians (646), French (554), and Americans (464).
The most popular industry for foreigners to be working in with a work permit are the hotel industry, with 1,198 registered foreign workers, the tourism industry with 1,039, and schools with 703.
Ms Yaowapa said there were 39 careers in Thailand that the government restricted for Thai people only. Foreigners were not allowed to do these jobs, she said, and those that did would be working illegally.
“I will not allow foreigners to do these jobs that are kept for Thais,” Ms Yaowapa said.
However there were a lot of grey areas, she said, such as the issue of “sitting guides.”
“Sometimes there are two tour guides on the same bus – one is Thai and one is foreign. They say the foreigner is a translator, for guests who speak that language. The same as foreigners who sell items in shops – they may not sell things but are used to communicate with customers.”
Last week Maj Gen Choti Chavalviwat, Commander of Phuket Provincial Police, announced an investigation into tour agencies, massage parlours and restaurants, as well as other businesses which are foreign-owned or employ many foreign staff.
The Department of Labour, in conjunction with Phuket Immigration and the Phuket Police, started checking companies on January 31, based on random checks or tip-offs from the public.
The main focus will be on businesses that are foreign owned or operated, but Thai businesses that employ large numbers of foreigners will also be checked.
Phuket Governor Maitree Intusut said that local people in Phuket should support the investigation by reporting any illegal foreign workers.