KUALA LUMPUR (Reuters) -The United States has barred imports from Malaysian glove maker Supermax Corp over alleged forced labour practices, the fourth Malaysian firm to face such a ban in the past 15 months.

Malaysian factories – which make everything from palm oil to medical gloves and iPhone components – have increasingly come under scrutiny over allegations of abuse of foreign workers, who form a significant part of the manufacturing workforce.

The U.S. Customs and Border Protection (CBP) issued a “Withhold Release Order” that prohibits imports from Supermax based on reasonable information that indicates the use of forced labour in its manufacturing operations, the CBP said in a statement on Wednesday.