A late businessman accused of bribing some key aides to President Park Geun-hye and politicians is suspected of ordering a cover-up before committing suicide, prosecutors said Friday.

Sung Woan-jong, chairman of a minor construction firm, Keangnam Enterprises Inc., killed himself earlier this month, leaving behind a list of people he allegedly bribed, including Prime Minister Lee Wan-koo.

Lee, who had declared an all-out war on corruption last month, offered to step down earlier this week.

President Park Geun-hye is expected to accept his resignation soon after her return home from a four-nation South American tour early next week.

Sung's death has presented a roadblock to the investigation into his alleged cozy ties with Lee and other influential figures.

Earlier, prosecutors arrested two of his aides who they believe have the most knowledge on the matter after the late businessman himself. The two, however, have been suspected of trying to hide evidence that may reveal the underhanded dealings.

A huge portion of computer files at Keangnam headquarters was missing, and closed-circuit televisions had been turned off, apparently to hide any trace of the evidence destruction.

Prosecutors suspect the evidence tampering had been ordered by the late chairman.

Sung was under investigation for embezzlement when he committed suicide. He hanged himself on April 9 just hours before a court hearing that would have determined the legality of his arrest.

A day before his death, he organized a press conference to refute the allegations and claimed he had been victimized. (Yonhap)