South Korean prosecutors said Thursday they launched a probe into Deutsche Bank's local brokerage unit in connection with last November's market plunge, following the financial watchdog's partial ban on its operation in the nation over alleged stock manipulation.

The prosecution's move comes at the request of the Financial Services Commission (FSC) that Wednesday announced its plan to ban the Germany-based financial giant's local securities unit from trading derivatives for six months as punishment for making an illegal gain by driving down the key stock index starting from April.

Deutsche Bank's Seoul branch has been investigated by the financial regulator over massive locally placed sell orders that led to the benchmark Korea Composite Stock Price Index's (KOSPI) 2.7 percent plunge in the last few minutes of the session on Nov.11, the expiry date of stock index options.

The Seoul Central Prosecutors' Office said it will first review the stock trade documents submitted by the FSC and Deutsche Bank's Seoul branch and then summon five senior bank executives to investigate their role behind the carefully planned stock manipulation scheme. (Yonhap News)