An observation and study group led by China's central bank has visited the two biggest companies in the country running online financial business.

The mission prompted speculation that legislation may be introduced to cover the Internet financial sector, the Shanghai Securities Journal reported on Tuesday.

The group, led by the People's Bank of China, visited Lufax, an online financing platform under China Ping An Insurance Group, and also went to e-commerce giant Alibaba, which has introduced several online financial services this year.

The group included representatives from seven central government departments, including the China Banking Regulatory Commission and China Securities Regulatory Commission.

The PBOC, the central bank, said in a report that Internet financing has several advantages, including higher transparency, lower costs, wide participation and convenient payments. But it also said that supervisors are facing a big challenge in controlling risks in the new financial sector.

Experts have suggested that clearer standards should be set for firms running online financial business, including a lowest risk margin to protect investors' interests.

The group did not give a timetable for legislation, but said it will strengthen supervision of the online financial sector based on the research results, the Shanghai Securities Journal reported.