(Reuters) -- U.S. government investigators have interviewed workers at Goodyear Tire & Rubber Co.'s Malaysian factory about their working conditions, employees told Reuters, intensifying scrutiny of potential labor abuses by the tire maker in the country.

The questioning by the Department of Homeland Security could lead to U.S. prosecutions of one of the world's biggest tire makers, which faces related lawsuits and two ongoing investigations by regulators in Malaysia and the United States, each looking into potential exploitation of foreign workers.

Five current and former Goodyear Malaysia staff said Homeland Security Investigations agents have asked about their working and living conditions, details of court cases they filed against Goodyear, a police complaint alleging threats from Goodyear staff and workplace accidents.

In video calls over the past 11 months or more, the agents from the main criminal investigation unit of the Department of Homeland Security also requested documents relating to their employment, said the workers, who asked not to be identified because they feared reprisals.

Reuters could not determine the specific violations that HSI is seeking to establish.

HSI said it does not comment on ongoing investigations.

Ohio-based Goodyear said it was committed to ensuring its supply chain practices adhered to laws and to its own policies.

"Goodyear and Goodyear Malaysia are currently undertaking a thorough review of the matter, including retaining an independent social auditing firm to inspect working and housing conditions," Goodyear told Reuters in an emailed statement. Goodyear did not identify the audit firm.

The HSI questioning follows initial allegations filed in three complaints by 185 migrant workers from Nepal, India and Myanmar - including the five who spoke to Reuters - against Goodyear Malaysia in the country's industrial court in 2019 and 2020. They alleged unpaid wages, citing non-compliance with a collective agreement, wrongful deductions and threats to migrant workers.

In 2020 and in June, the court ordered Goodyear to pay back wages to some workers and comply with the agreement. The company has appealed the verdicts.

Goodyear told Reuters it has now committed to a settlement with the workers represented in the labor dispute.

The company argued in court that foreign workers are not entitled to the benefits of the collective agreement because they are not union members. It has declined to comment on the allegations.

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