[Photo/Xinhua] Almost half its constituent political groups revoked their membership in Hong Kong's Civil Human Rights Front after media reports showed the city government had started to investigate the mass protest organizer. Sing Tao Daily, a Chinese-language newspaper in Hong Kong, reported on Sunday according to an anonymous source, 21 groups would leave the front, which used to have 43 members. The Professional Teachers' Union, Hong Kong's largest teacher organization, announced on Sunday its decision to withdraw from the front. Others cutting ties recently included the Civic Party, according to the South China Morning Post. The withdrawals happened after Lianhe Zaobao, a Chinese-language newspaper in Singapore, reported recently the Hong Kong government started to investigate accusations the front was being supported by the National Endowment for Democracy, a Washington-based NGO. John Knaus, the senior director for Asian affairs at the National Endowment for Democracy, was sanctioned by the Chinese government last year over egregious behavior on Hong Kong issues, along with three other people. According to the Lianhe Zaobao report, the front has a close relationship to the NED and its subsidiary, the National Democratic Institute, though it has denied any financial support from overseas governments or organizations since its foundation in September 2002. A document from the US research organization Ron Paul Institute for Peace and Prosperity showed the NED has financially supported many groups in the protests in 2019, offering Hong Kong Human Rights Monitor $90,000. Along with the Hong Kong Human Rights Monitor, the NED has kept a close relationship with other groups in the front for many years, such as the Civic Party, according to the document. Groups supported directly or indirectly by overseas individuals, groups or organizations may be found to violate the National Security Law for Hong Kong if that behavior is shown to lead to serious results endangering China's national security. Media reports also showed the front had organized mass rallies, many of which led to violence, and had never registered with the government. Either might have violated the city's Societies Ordinance.