Frameworks are in place to deal with the mistreatment of foreign workers but the onus is on employees to report it, the Cook Islands government says.
A former Deputy Prime Minister, Norman George, is calling for the creation of a unit to investigate mistreatment, saying workers were being underpaid, forced to work long hours, given sub-standard accommodation and treated like slaves.
Secretary for Internal Affairs Bredina Drollet said workers could report mistreatment and be protected by confidentiality but Mr George said the workers were still vulnerable.
He said some workers, who typically work in the service industry, were threatened with being sent off island and some had their passports taken by employers.
Ms Drollet said that was illegal.
"It's against the law. It would be classified as theft. An employer can take the passport to make a copy and do the things they need to but they cannot hold the passport. If they hold the passport, that worker has grounds to take that to the police, for theft."
Bredina Drollet said there were not the numbers of reported cases to suggest it was a major issue and fiscal constraints meant an investigative unit would be unlikely.