Labour Minister Phiphat Ratchakitprakarn ordered a crackdown on foreigners working in occupations restricted to Thai nationals after the ministry made more than 4,400 arrests for the offence in the past nine months.
Mr Phiphat had ordered agencies to cooperate on protecting the jobs of domestic workers in the country.
The order came after a large number of arrests involving illegal foreign labourers, said Mr Phumphat, who added one of the main factors contributing to the issue was employers wanting to save on recruitment costs.
Moreover, he also blamed the failure of some legal officers to press charges which worsened the problem.
He said the ministry would work with the police and Department of Employment (DoE) to "find, charge, fine and repatriate" illegal workers.
From Oct 1 to June 13, 4,437 foreigners were found working in strictly prohibited "List-1" occupations for expats, such as vendors, barbers, traditional masseurs, secretaries and chauffeurs.
The ministry also found 4,720 foreigners working in List-3 conditionally prohibited occupations, such as bricklaying, carpentry, construction, agriculture and fishing.
It also found 22,414 foreigners working in List-4 conditionally prohibited occupations such as shop sales assistants and manual labour.
