Four key members of Shanxinhui, a company suspected of organizing and leading a pyramid scheme, have been detained by police in south China's Hainan Province.

According to Hainan police on Monday, Shanxinhui allegedly manipulated and talked people into taking part in pyramid selling and cheated them out of huge amounts of property under the guise of helping the poor.

Several suspects including Zhang Tianming, the mastermind of Shanxinhui, have already been put under coercive measures, which may include summons by force, bail, residential surveillance, detention or arrest.

Zhang, 42, founded Shenzhen Shanxinhui Culture Communication Co. Ltd in south China's Shenzhen City in May 2013, and Hainan Shanxinhui in May 2016.

In July, Guangdong police seized 230 members of Shanxinhui. Beijing police also arrested 63 after members of the pyramid scheme gathered in the capital city.

Pyramid schemes have been expanding widely in China through social networks in recent years.

Police investigated 2,826 pyramid scheme cases in 2016, 19.1 percent more than that in 2015, according to the Ministry of Public Security.

From 2005 to 2015, 21,904 pyramid schemes were investigated and 990 million yuan (140 million U.S. dollars) confiscated.