Prosecutors investigating slush fund and tax evasion allegations against Hanjin Group chairman Cho Yang-ho are raiding the offices of Hanjin's affiliates.

Investigators from the Seoul Southern District Prosecutors' Office raided Hanjin KAL and Jungseok Enterprise located in downtown Seoul Thursday morning.

Hanjin KAL is the holding company of Hanjin Group while Jungseok Enterprise is an unlisted firm that manages real estate affairs for the Cho household. Chairman Cho and his family members are shareholders of the firm. 

Earlier last month, Cho was accused of not paying inheritance taxes worth tens of billions of won.

The National Tax Service is believed to have secured evidence showing that Cho and his brothers evaded taxes of over 50 billion won in the course of inheriting overseas-based assets from their father.