The logo of the Korea Customs Service / Yonhap

Korea's customs service said Thursday it has collected 1.3 billion won ($880,000) from delinquent taxpayers through a joint investigation with the tax agency.

Under the joint investigation conducted by the Korea Customs Service and the National Tax Service, the two agencies shared their respective databases to track the concealed assets of delinquent taxpayers.

The shared database included information on the taxpayers' asset concealment, as well as comparisons between their actual residences and the addresses registered for their personal customs clearance codes with the customs service.

Through the investigation, the agencies found one delinquent taxpayer running a business under the father's name, discovering cash and checks hidden in a travel suitcase.