The size of shadow banking in South Korea is estimated to have grown to more than 1,500 trillion won($1.35 trillion) last year, data showed Sunday.

The data submitted by the central bank to Justice Party Rep.

Park Won-suk showed that the size of the country's shadow banking sector expanded 11.6 percent on-year to 1,503 trillion won as of the end of last year.

Shadow banking refers to financial activities through non-banking channels, including hedge funds, real estate trust funds and off-balance sheet investments and are outside of regulatory oversight that is applied to banks.

By sector, securities firms accounted for the biggest portion at 362 trillion won, followed by collective investment vehicles at 359 trillion won, the data said.

A report by the Financial Stability Board, meanwhile, showed that the country's shadow banking sector accounted for 109.3 percent of its gross domestic product, the seventh highest of the tallied 26 countries.

The Netherlands topped the list at 759.2 percent, followed by Britain at 347.9 percent and Switzerland at 261.2 percent. (Yonhap)