South Korea plans to file a criminal complaint against the head of Volkswagen AG and Audi AG’s local unit later on Tuesday, saying that a recall plan for emissions-cheating cars fell short of legal requirements.

The complaint, to be filed by the environment ministry against Johannes Thammer, managing director of Audi Volkswagen Korea, is the latest in a flurry of legal actions around the world against Volkswagen after it admitted in September to falsifying U.S. emissions tests on some of its diesel cars.

After conducting its own emissions tests, South Korea in November fined the German automaker a record 14.1 billion won ($11.7 million) and ordered a recall of 125,522 vehicles.

On Jan. 6, Volkswagen submitted a proposal to fix the vehicles including the Tiguan, South Korea’s top-selling import model, at the request of the ministry.

But the ministry said in a statement on Tuesday that the plan failed to explain why the problem occurred and how it would be fixed, as required by law.

The ministry said Thammer and other VW officials including VW’s powertrain development chief Friedrich Eichler visited the ministry earlier on Tuesday to offer a technical briefing on the proposed fix.

A spokesman for VW in South Korea said the company had not received notice of the complaint.

“Audi Volkswagen Korea is doing its utmost to resolve the emissions issue,” the company said in a statement on Tuesday, before the ministry’s announcement.

Under South Korean environmental law, a guilty conviction could result in a prison term of up to five years and a fine of up to 30 million won, the ministry said.

South Korea is the world’s eighth-biggest diesel car market, according to auto parts maker Bosch.

German cars have surged in popularity in recent years in Asia’s fourth-biggest economy, driven by fuel-efficient diesel models that became more affordable following a 2011 free trade deal between the country and the European Union.

Volkswagen and Audi together top the imported car sales rankings in South Korea. Their combined sales jumped 17 percent to 68,316 vehicles last year.

This month the U.S. Justice Department sued Volkswagen for up to $48 billion, accusing it of violating environmental laws. The automaker also faces lawsuits from shareholders and customers.

($1 = 1,210.3 won)