Police in China arrested 21 employees at the country’s largest online finance business late Sunday, in what could be the biggest financial fraud in Chinese history, the Associated Press (AP) reported, citing local media.

An online peer-to-peer lender, Ezubao, was accused of running a scam that duped almost 900,000 investors for a total of about 50 billion yuan ($7.6 billion), Reuters reported, citing China's official Xinhua News Agency. Chinese police reportedly said they had sealed, frozen and seized the assets of Ezubao and its linked companies as part of the investigation.

Among those reportedly arrested was Ding Ning, chairman of Yucheng Group, which owns Ezubao. The online financing company rose from obscurity to become China’s largest business of its kind over a period of about 18 months, according to the AP.

Xinhua called the fraud a Ponzi scheme while the South China Morning Post reported that Ding, 34, used the money fleeced from investors to finance his own lavish lifestyle and to develop a positive company image.

The company was launched in July 2014, according to Reuters, and over 95 percent of the projects listed on the financing platform were allegedly fake. The website offered investors annual returns between 9 and 14.6 percent, but most of the investors’ money was used to pay old debts, the Straits Times reported, citing Xinhua.

China’s fast-growing wealth management industry, worth $2.6 trillion, according to Reuters, is loosely regulated. Promising returns higher than traditional banks, it has attracted a deluge of investments from the country’s burgeoning middle class.