"I think it's definitely more serious," Teng said. "We have heard nothing from Tang Jitian since Dec. 10, so it looks like an enforced disappearance."
He said the situation of Chinese dissident and former legal advocate Guo Feixiong, also known as Yang Maodong, appeared to be similar. Guo has been incommunicado since writing an open letter to Chinese premier Li Keqiang, asking him to lift a travel ban and allow him to visit his critically ill wife Zhang Qing in the United States, Teng said.