A top economist has joined the growing list of China’s elite to have disappeared from public life after criticizing Xi Jinping, according to The Wall Street Journal. 

Zhu Hengpeng served as deputy director of the Institute of Economics at the Chinese Academy of Social Sciences (CASS) for around a decade.

CASS is a state research think tank that reports directly to China’s cabinet. Chen Daoyin, a former associate professor at Shanghai University of Political Science and Law, described it as a “body to formulate party ideology to support the leadership.”

According to the Journal, the 55-year-old disappeared shortly after remarking on China’s sluggish economy and criticizing Xi’s leadership in a private group on WeChat.