Six business have been caught employing illegal workers following immigration raids in Swansea and Neath.
Fifteen people from China, India, Iraq, Bangladesh and Malaysia were found at restaurants and take-aways in the area by UK Border Agency officers.
The businesses now face fines of up to £10,000 for each worker.
The raids were carried out as a result of intelligence gathered by the agency and all 15 workers now face being removed from the UK.
On Monday officials went to the Thye Heng Chinese takeaway at Pontarddulais and found two illegal workers.
The same night they also went to the Ming Kee Chinese takeaway in Ystalyfera and found three people and the Zafran Indian Restaurant in Skewen, near Neath, where there were four.
On Wednesday three more raids at the Penclawdd Tandoori in Penclawdd, BBQ King Diner on Swansea's St Helen's Road and the Oceana Kebabs on the Kingsway caught a further six illegal workers.
Minimum wage
Some were failed asylum seekers, some had stayed in the UK after their papers had expired while others had gained entry illegally.
Eddy Montgomery, the agency's acting regional director for Wales, said: "These operations show that our officers are extremely active across south Wales in cracking down on illegal working.
"We take action against the illegal workers by seeking to remove them from the UK, but we also clamp down on anyone who is proved to have employed them by issuing large fines.
"Businesses which employ illegal workers are able to undercut competitors by paying below the minimum wage and we often find they are also by-passing health and safety laws."