South Korea's government said Tuesday it is considering banning sales of two car models sold in the country by a local subsidiary of Nissan Motor. Co., accusing it of submitting fabricated documents to get certification.

The Environment Ministry said it detected problems in the certification documents for the Qashqai, a sports utility vehicle produced by Nissan, and the Infiniti Q50, a sedan manufactured as part of an alliance between Nissan, Mitsubishi Motors Corp. and Renault SA of France. The documents were submitted by Nissan Korea Co.

Depending on Nissan Korea's response, the ministry said, it may seek to prosecute the company for violating South Korea's Clean Air Conservation Act.

It said it is taking similar action against two German automakers, namely BMW AG and Porsche AG.

Nissan Korea told local media that it had voluntarily suspended sales of some cars and will take appropriate measures after undertaking internal investigations.

The company is suspected by the Environment Ministry of submitting fake test reports on the performance of equipment that notifies a driver of engine abnormalities.

In May, the Environment Ministry fined the firm 340 million won (about $287,000) for allegedly fabricating emission-test results for Qashqai vehicles and ordered a recall on 824 units.

The ministry moved in June to ban Qashqai sales in South Korea, but a court temporarily suspended that ban the following month after Nissan, which denied any wrongdoing in the case, sought an injunction.

Nissan paid the fine, but hearings on the case continue.

The government launched its investigation into 20 models of diesel cars sold in South Korea after it was revealed German carmaker Volkswagen AG used "defeat device" software to cheat U.S. emissions tests on its diesel vehicles.