Japan motor-vehicle maker Toyota Motor Corp. is under investigation by Thailand for allegations one of its consultants attempted to bribe local officials in a tax dispute.

Toyota is aware of the investigation into its Thailand subsidiary and has submitted a report to the U.S. Department of Justice and the U.S. Securities Exchange Commission. The company said in the filings it received reports of "possible anti-bribery violations" involving its partners in Thailand.

"We take any allegations of wrongdoing seriously and are committed to ensuring our business practices comply with all applicable government regulations," Toyota said in a statement.

Thailand is one of Toyota's largest markets and its biggest manufacturing hub in Southeast Asia. The company makes many of its cars, pickups and vans in the country - for both local sale and export.

Thailand said it would take swift action against any of its officials - including judges - found to have taken bribes.

"If the Court of Justice has received information, or explicitly found that any judge committed an act of corruption, whether it is about bribery or not, (it) will resolutely investigate and punish any action which dishonors judges, undermines the neutrality of the court or causes society [to] lose faith in the justice system," it said.

Investigators said the alleged bribery was tied to a dispute between Toyota Motor Thailand Co. Ltd. and the inland revenue department and amounted to approximately $320 million and is associated with the importation of parts for the company's Prius hybrid vehicle.

In 2015, Toyota Motor Thailand was accused by customs officials of understating taxes for Prius parts imported from overseas. Toyota allegedly imported complete knocked-down kits used to assemble vehicles.

Knocked-down kits are subject to a discounted tax rate significantly lower than fully assembled vehicles. In the same year Toyota filed an appeal to reverse a customs decision to impose higher duties on the CKD kits.