The raids were carried out because the Financial Services Commission (FSC) had accused Samsung BioLogics of intentionally violating accounting rules, according to the Yonhap news agency.
The prosecutors searched the offices of one of the group’s most important units, Samsung C&T Corp, as well as the data centre of Samsung’s IT service provider, Samsung SDS Co.
The prosecutor's office launched its investigation more than three months ago upon finding suspicious account documents for Samsung BioLogics from 2015 that showed a sudden spike in profits after years of losses. This shift took place after Samsung Bioepis, Samsung BioLogics' joint venture with the US-based Biogen Inc., revised the method for calculating its value.
The possible fraud reportedly benefited Samsung Group's heir apparent, Lee Jae-yong. According to the South Korean financial regulator, the suspected fraudulent accounting could amount to 4.5 trillion won ($4.35 billion).
Samsung BioLogics has denied the accusations, pointing out that the methodological changes in the company were in line with international accounting standards.