A private financial consumer group said Monday that it would bring SK Group chairman Chey Tae-won and his mistress to the prosecution on charges of embezzlement and violation of the local foreign exchange control law.

The Financial Consumer Agency referred the case to the Seoul Central District Prosecutors’ Office, alleging that the SK chairman’s 41-year-old mistress, identified by her surname Kim, made an unreasonably quick fortune through illegal transactions, suspecting Chey’s embezzlement.

The controversy ignited last year when Kim bought an apartment constructed by SK Engineering and Construction for 1.55 billion won ($1.28 million) in January 2008, and resold it to another SK subsidiary at an inflated price in April 2010. Kim, a U.S. citizen and nonresident here, sold the asset to Bergaya International, a Singapore-based subsidiary of SK Group, for 2.4 billion won, snagging a profit of almost 1 billion won in 27 months.

The controversy further intensified after the same SK Apelbaum II apartment of the same 245-square-meter size was found to have been sold for 1.8 billion won in December 2015, undermining SK’s claim that the apartment was bought considering due costs.

Last week, an SK official said the apartment deal was a normal transaction, intended to provide housing to Singaporean employees of Burgaya International relocated here.

The official websites of Apelbaum and Bergaya International are currently shut down. 

During the transaction, both sides failed to report the purchase to the country’s central bank. The local foreign exchange control act, which aims at preventing tax evasion crimes, requires all nonresidents to inform the Bank of Korea of any acquisition of real estate properties in Korea. The law also applies to the Korean companies operating on foreign soil.

The consumer group’s move comes after Korean financial watchdog, the Financial Supervisory Service, separately launched a crackdown on the controversy, foreboding a rocky legal battle for SK, in addition to the group chairman’s existing divorce case.

Late last month, Chey publicly confessed to having an extramarital affair for several years with Kim, with whom he had a child.  

By Chung Joo-won (joowonc@heraldcorp.com)