KUALA LUMPUR: Rights group Liberty Shared has asked United States customs authorities to investigate the Malaysian operations of American tyre maker Goodyear Tire & Rubber Co over accusations of abusive labour practices, the group told Reuters.

The Hong Kong-based anti-trafficking group said its June petition to U.S. customs, based on lawsuits and police reports by migrant workers, was probably the first such effort against a subsidiary of an American-owned company in southeast Asia.

"The conditions and treatment they have endured seem to satisfy the International Labour Organisation's forced labour indicators," the group's managing director, Duncan Jepson, said in its first comments to media on the issue.

Goodyear, one of the world's largest tyre makers, said it was not aware of any petition on the matter, while the U.N. agency did not immediately respond to a request for comment.

Malaysia, which employs millions of foreign workers, has faced growing accusations of exploitative labour practices, and received the worst ranking this month in an annual U.S. report on human trafficking.

Similar petitions to U.S. customs, including one last year by Liberty Shared regarding Malaysian palm oil producer Sime Darby Plantation, have led the United States to block imports over suspected use of forced labour.

Goodyear's Malaysian unit was asked by an industrial court to pay back wages to migrant workers and comply with a collective pact, after dozens of foreign workers sued over unpaid wages and unlawful overtime, Reuters reported in May.

It has challenged two verdicts in the High Court.

In its response to the rights group's comments, Goodyear added that it had strong policies to protect human rights.

"We take seriously any allegations of improper behaviour and are committed to ensuring that our business practices and those of our associates, operations and supply chain adhere to all applicable legal requirements and the requirements in our policies," a spokesperson said in an email.

In the past, the company has declined to comment on the workers' accusations, citing the court process.

Malaysia's largest fund manager, Permodalan Nasional Berhad, which owns 49% of Goodyear Malaysia, did not immediately respond to a request for comment.

The U.S. Customs and Border Protection (CBP) said it does not comment on whether specific entities are being investigated.

Jepson said he understood U.S. customs was pursuing the petition he filed. In an email, the CBP told him it had received the petition on forced labour conditions and was reviewing the information. Reuters reviewed the email.

The July 19 email does not name Goodyear Malaysia, but Jepson said the petition was only about the company, based on civil cases and police reports filed by its workers.

Last year, after Liberty Shared accused Sime Darby of forced and child labour, the CBP blocked its products from entering the United States.

Sime Darby has appointed auditors to evaluate its practices and said it would engage with the CBP to address the concerns.