Immigration officers made several arrests of foreign nationals from restaurants in Newton Stewart and Stranraer last weekend.
The action came as part of a Home Office operation and saw Little India in Newton Stewart targeted along with Hong Kong City and Bollywood in Stranraer.
Home Office immigration enforcement officers detained two Bangladeshi men, a Pakistani man and a Chinese man .
The Hong Kong City faces a potential financial penalty of up to £20,000 unless it can show right-to-work document checks were carried out.
Three of the men are facing deportation and are in custody until this can be arranged.
The fourth man has been temporarily released while his case is progressed.
A Home Office spokesperson said: “Our dedicated specialist teams have the expertise to catch you and if the correct checks have not been carried out you will pay a heavy penalty,” she said.
“Illegal working cheats the taxpayer, undercuts honest employers and often exploits some of society’s most vulnerable people.”
Police Scotland supported the operation.