South Korea's environment ministry requested the prosecution Tuesday to investigate the local unit of Volkswagen over its plan to recall diesel-powered vehicles sold here, claiming the measure is insufficient.

The ministry said that it took the action after determining that Volkswagen's recall plan submitted on the government-set deadline of Jan. 6 is "insufficient."

In November, the ministry ordered Volkswagen to recall about

125,000 vehicles whose emissions were found to be faked through the so-called defeat device. It also fined the company 14.1 billion won and demanded additional data.

Volkswagen has vowed to start its recall process during the first half of the year.

As for faking emission results and producing excessive amounts of hazard gases into the air, the ministry said that it will consult legal experts to determine whether to push for additional criminal charges.

Meanwhile, the transportation ministry said that it plans to launch its fuel efficiency testing of Volkswagen vehicles involved in the emissions scandal next week.

The ministry earlier concluded that there is a "correlation"

between the German carmaker's manipulated emissions for some of its diesel vehicles and their fuel efficiencies. It is in charge of policies related to the fuel efficiency of automobiles.

Under the current regulations, a recall can be ordered with a fine if the discrepancy in fuel efficiency tests exceeds 5 percent of the officially approved efficiency. (Yonhap)