The United States is investigating Malaysian glove makers Hartalega Holdings (HTHB.KL) and a unit of Supermax Corp (SUPM.KL) over allegations of forced labour, the Edge Weekly reported on Saturday.
The Edge cited two letters sent by US Customs and Border Protection (CBP) to labour rights activist Andy Hall, who petitioned the agency to investigate the firms.
In both letters, the CBP said it has sufficient information to "investigate the merits" of Hall's allegations, the Edge reported.
Hartalega did not comment on the US probe but said it strictly adhered to labour laws and regulations on recruitment of migrant workers. It also said its efforts to combat forced labour are guided by local and international policies.
"We understand that social compliance is an ongoing journey and we always strive for improvement," it said in an email to Reuters.
Supermax did not respond to Reuters' queries. The Edge said it did not get a reply from Supermax.
The CBP said in an email it does not comment on whether specific entities are under investigation.
Hall confirmed to Reuters that he had received the letters.
Malaysian firms have increasingly come under regulatory scrutiny over allegations of abuse of foreign workers, who form a significant part of the country's manufacturing workforce.
In the last year, the CBP banned US imports from three Malaysian firms on suspicions of forced labour: Top Glove (TPGC.KL), the world's biggest latex glove manufacturer, and two top palm oil producers.
Top Glove said in April it has resolved all indicators of forced labour found at its factories. But the ban remains in place, and the agency this month seized two shipments of Top Glove products that entered the United States.
Reuters reported on Friday that Canada is also investigating allegations of forced labour in Malaysia's palm oil and glove manufacturing industries.