Fraud is the biggest risk for China's flourishing peer-to-peer online lending business, senior financial executives warned on Thursday.

Gregory D. Gibb, chief executive of Shanghai Lujiazui International Financial Asset Exchange, said the top priority for the online lending business is to protect users' interests as almost all lenders on China's P2P platforms are individual investors.

"Investors in the P2P lending business in developed countries such as the United States are mostly professional institutional investors, which is different from the reality in China," he said.