Trade union group Wales TUC has slammed employers who are not treating migrant workers fairly, according to reports.
A report into the employment of migrant workers in the principality uncovered that many people working in low-skilled jobs are suffering from inadequate treatment, reports the Western Mail.
Apart from the fact that many employers allegedly fall foul of pay and other employment conditions, workplaces also frequently fail to meet health and safety standards, it suggested.
The newspaper quoted a section of the report that said migrant workers are "undoubtedly being exploited" and work in "appalling conditions".
Commenting on the report, Wales TUC head of policy and campaigns Derek Walker told the Western Mail: "Too many unscrupulous bosses are getting rich by exploiting migrant workers."
He called for the "full force of the law" to act against such employers.
According to Wales TUC's website, migrant workers in the principality experience discrimination and exploitation on a regular basis.