Migrant Rights Protection Desk head Florida Sandanasamy said Tenaganita, which began as a women's rights advocacy organisation, expanded to include migrant workers' rights when it started getting many pleas for help from male foreign workers.
Last year, Tenaganita opened 259 case files, involving 2,153 migrant workers.
Florida said the NGO networked with the Bar Council's legal aid centre to handle cases and disputes.
"We deal with the Immigration Department and other government departments. We also handle things like lodging police reports."
Florida said a simple issue like unpaid wages could have catastrophic consequences for the affected worker.
The employer, more often than not, would cancel a worker's work permit the moment the complaint is filed.
"This means he is an undocumented foreigner. He has to go to the Immigration Department to seek legalisation.
"However, the department's policy only allows him to stay a maximum of three months if he is undocumented."
During that time, the worker is not allowed to work and has to pay RM100 a month to the Immigration Department.
"How is he to survive? Even if he can borrow the money, he is still undocumented, leaving him open to police arrest.
"He is then either charged for being an illegal or deported and the case is dropped. The employer gets away scot free," she said, adding this was why migrant workers needed to be unionised.