The South Korean unit of German carmaker Volkswagen apologized Thursday for an emission-rigging scandal and vowed to take “all necessary measures” including a voluntary recall of the vehicles in question.

The scandal erupted after it was revealed last month that Volkswagen Korea had sold some 120,000 vehicles with a device to cheat the pollution tests. To date, over 11 million cars worldwide are believed to have been installed with hidden software that can switch on pollution controls when it detects the car is being tested.

Audi Korea, which is presumed to have sold some 29,000 of the rigged cars as part of the Volkswagen Group, issued a similar apology.

The rigged cars sold by the two companies in the country is tentatively tallied at over 120,000.

“I would like to take this opportunity to offer my sincere apology on behalf of Volkswagen Korea for breaking the trust of our Korean customers,” the company CEO Thomas Kuehl said in a parliamentary audit, after he issued the first official apology in Korea via newspaper advertisements.

“I also want to apologize for the late response. Due to complexity of the issue and different emission standards in Korea, it took a long time to investigate how many cars were affected. Be assured we will do everything to clarity and solve this issue as soon as possible,” he said.

He added that Volkswagen is fully cooperating with government officials worldwide including in Seoul to determine the exact cause of this issue.

He emphasized, however, that none of the cars currently being sold across the country have the device in question, and that the rigged cars do not show any safety-related defects when driven.

The companies were to send separate letters of apology to each of its customers. They did not mention the details about how to compensate the customers.

Kuehl told the lawmakers that details of the follow-up measures would be revealed after the government investigation is complete. Seoul’s Environment Ministry last week launched an investigation into the suspected models over the emission rigging.

Lawmakers also questioned him about the possibility of the product recall worsening the fuel efficiency of the cars, and if Volkswagen planned to compensate for it. Kuehl reiterated that he could not give a definitive answer yet, but vowed to address the issue after the probe is complete.

Volkswagen Korea has launched a website that helps customers determine if their car has been rigged, and Audi plans to launch a website for the same purpose.

The public apology was widely perceived as an attempt to address public discontent amid an ongoing investigation by the government.

Some 40 Volkswagen owners entered a joint lawsuit against the company in less than a week, with hundreds more expected to follow suit.

Volkswagen on Wednesday announced that it would launch a massive recall in January for vehicles affected by the emission tests scandal. Michael Horn, the U.S. head of Volkswagen, offered a “sincere” apology Thursday for the company’s use of rigging software ahead of his hearing with the House energy committee.

He also admitted that he came to be aware of the emissions-related problem with the cars last year.

By Yoon Min-sik(minsikyoon@heraldcorp.com)