Prosecutors raided the offices of Hankook Tire Technology, the nation's leading tiremaker, Thursday as part of their investigation into an alleged unfair intra-affiliate trading deal. Yonhap

Prosecutors raided the offices of Hankook Tire Technology, the nation's leading tiremaker, Thursday as part of their investigation into an alleged unfair intra-affiliate trading deal.

Investigators from the Seoul Central District Prosecutors Office seized relevant documents from the headquarters and offices of its affiliates in connection with suspicions of unfair business practices among the group's affiliates.

Prosecutors also searched the office of Cho Hyun-bum, the chairman of Hankook Tire.

The investigation comes after the antitrust regulator decided to impose a fine of around 8 billion won ($6 million) on Hankook Tire for allegedly purchasing overpriced tire molds from its affiliate, Hankook Precision Works.

The Fair Trade Commission (FTC) alleges the unfair business practice that lasted from 2014 to 2017 was aimed at helping the company solidify its presence in the market.

Over the period, the operating profit-to-sales ratio of Hankook Precision Works shot up to 32.5 percent from 13.8 percent tallied for an earlier four-year period, the FTC said.

Through the gains made through the shady deal, the regulator said Hankook Precision Works was also able to pay off its debt of 34.85 billion won incurred during its acquisition by Hankook Tire in 2011. (Yonhap)