Prosecutor General Lee One-seok ordered participants and beneficiaries in a suspected case of large-scale stock manipulation conducted through SG Securities Korea be thoroughly tracked down and punished.

After being briefed on the case from the head of the Seoul Southern District Prosecutors' Office on Wednesday, Lee called for further damage to public trust in the capital market to be prevented.

The top prosecutor also called for cooperation with the Financial Services Commission and the Financial Supervisory Service to crack down on unfair trading that distorted market order and inflicted significant damage to multiple investors.

Last Friday, prosecutors formed a joint team with financial authorities to investigate the suspicious trading after shares of eight local companies that had been steadily rising since April of last year suddenly began to plummet.

The stock plunge followed mass sell-offs through SG Securities Korea, the local branch of the Societe Generale Group of France.

Authorities suspect that a consulting firm inflated trading volumes and prices through matched orders, then dumped the stocks when regulators began to investigate.