Slideshow ( 2 images )

SEOUL (Reuters) - South Korea plans to impose a combined fine of 70.3 billion won ($63.1 million) on units of automakers BMW AG, Mercedes-Benz and Porsche citing violation of emission rules, the environment ministry said on Thursday.

Seoul Main Customs, part of the country’s customs agency, have also asked prosecutors to probe the three units for violation of customs law such as illegal imports, the ministry added.

The BMW unit will be fined 60.8 billion won for “falsifying” documents on emission test results and not obtaining approval for changes in emission-control components before their cars were sold, the Ministry of Environment said in a statement.

The Mercedes-Benz and Porsche units will be fined about 7.8 billion won and 1.7 billion won respectively for not obtaining approval for changes in emission-control components before cars were sold.

Certificates of fuel efficiency will be canceled by mid-November and sales to be stopped for 28 BMW models, the ministry said. This measure will not affect cars that have already been sold, it added.

The BMW unit said it is “faithfully cooperating” with the government on their probe into certificate documentation errors, and will take necessary measures.

A few of the 200,000 cars that had been imported through customs between 2012-2017 had been declared for customs before approval was given or changes in components were reported, the Mercedez-Benz unit said.

Internal processes will be strengthened to prevent such instances in future, it added.

A spokeswoman for the Porsche unit said the ministry’s measure will not have any impact on their business, as the fine addresses component changes between 2010 and 2015, and all cars being sold now are properly certified.