INCHEON (Yonhap) -- A 57-year-old executive of the South Korean unit of U.S. carmaker General Motors Co. has been indicted on charges of receiving some tens of millions of won in kickbacks in return for business favors, prosecutors said Wednesday.

The Incheon District Prosecutors' Office said the executive in charge of labor management cooperation, whose identity was withheld, allegedly gave favors to a certain company when purchasing gifts for employees in 2015. Prosecutors suspect he received 30 million won ($26,000) in return.

A former company executive, 59, who resigned last month when the investigation began was also indicted for similar allegations.

Prosecutors said several leading members of the company's labor union are also suspected of collaborating with the executives.