BEIJING, Jan. 15 -- Supervision and risk analysis are urgently needed on China's shadow banking businesses, a central bank official said on Wednesday.

Sheng Songcheng, financial survey and statistics chief at the People's Bank of China, the central bank, said that his team has been negotiating with other government departments on improving statistical work, research and analysis on shadow banks.

"No matter which department or agency the supervision work falls to, it must take full responsibility," Sheng said.

The supervisory work aims to guide shadow banks to better serve the real economy with risks contained, he said at a press conference in Beijing on Wednesday.

The official's remarks came after media focus in the past week about a yet unconfirmed government document that targets greater supervision of shadow banking businesses.

The document classified the existing forms of shadow banking businesses in the country and specified the supervisory body under a specific case, aiming to put on hold expansion of financial risks.

The businesses, including Internet finance companies, third-party wealth management institutions, finance guarantee companies, micro-credit firms, and other intermediaries, operate under low supervision or no supervision, according to the document.

Analysts said that shadow banks are results of financial innovations that can guarantee money supply amid tight liquidity, but it involves risks.

"Shadow banks are closely related with trust companies and banks. About one fourth of their loans might have gone to the real estate industry and more than half of the remainder might be related with local government debts," said Zhao Qingming, a professor at the Beijing-based University of International Business and Economics.

The central bank's vice governor Pan Gongsheng said earlier that local governments have turned to more expensive lending from shadow banks due to stricter requirements regarding banks lending to local government financing vehicles.

"When property prices suddenly fall or debt risks in local regions break out, the risks of shadow banks will emerge," Zhao said, adding that he believes authorities will take timely measures to address potential problems regarding shadow banks.

Due to the lack of a sound statistical system for shadow banks, their scale remains a mystery in China. But a report from the Chinese Academy of Social Sciences showed the value was 14.6 trillion yuan on the basis of government calculations, and 20.5 trillion yuan based on market data as of the end of 2013 .

The value based on market calculations accounted for 40 percent of the nation's gross domestic product and 16 percent of the banking sector's total assets.