Prosecutors raided South Korea's main stock exchange as part of a probe into alleged accounting fraud by Samsung BioLogics.

According to the prosecution, the Seoul Central District Prosecutors' Office sent investigators on Friday to search the Korea Exchange(KRX) in western Seoul. The investigators seized computer hard disc drives and other materials related to Samsung BioLogics. 

Prosecutors also raided the offices of Samsung S&T and Samsung SDS on Thursday regarding a probe into the biopharmaceutical company. 

The prosecution is investigating allegations that Samsung BioLogics intentionally violated accounting rules by inflating the value of its subsidiary, Samsung Bioepis, ahead of BioLogics' initial public offering(IPO) in 2016.

The prosecution suspects the KRX eased IPO rules at the time to make BioLogics eligible for listing on the tech-heavy KOSDAQ market.