The growing number of migrant workers in Northern Ireland are being exploited, says a study by the Irish Congress of Trade Unions.
It also highlighted what it said was widespread racism and sectarianism experienced by those who have travelled to the North in search of work.
Interviews with migrant workers showed that some were lied to by those recruiting them in their home countries to work in Northern Ireland. Rates of pay and overtime turned out to be less than offered, and those who complained faced being sacked by the agency employing them, the report said.
"There is ample evidence of unlawful discriminatory practice by some companies in the recruitment agency sector, and it is imperative that this be addressed," the report stated.
"Ictu should lobby and campaign for a formal investigation into the activities of recruitment agencies recruiting migrant workers to Northern Ireland."
The report said it found "very widespread experience of racism and sectarianism. This often occurs outside of work, but it is commonplace in the workplace as well."
It also pointed to family issues such as problems with housing, education and access to benefits.
PA