Chinese police arrested 21 employees at China's largest online finance business on suspicion of fleecing 900,000 investors for $7.6 billion, in what could be the biggest financial fraud in Chinese history.

State media outlets reported the arrests late Sunday and state broadcaster CCTV aired purported confessions from two former employees at Ezubao, an Anhui Province outfit that rose from anonymity to become China's largest online financing platform in the span of about 18 months.

Investigators found about 95 percent of the investments offered on Ezubao were fake.

Chinese authorities have struggled to regulate the sudden boom of online investment schemes that promise higher returns than those at traditional banks. The industry has attracted a flood of investment from China's middle class.