Hada, pictured here with his son Uiles and his wife Xinna before his arrest, is the founder of the Southern Mongolian Democracy Alliance. It’s an underground group seeking independence in the region. He was imprisoned in China on charges of espionage and “separatism.”

Last month, his wife and son were also detained by public security officials. They, too, have not been heard from since, according to the New York-based Southern Mongolian Human Rights Information Center.

This picture, of Hada with his wife and son, was posted on a Chinese website on Saturday - the day after he was supposed to be released. It was labeled “family reunion” and marked with Friday’s date. A Chinese security official also handed a DVD containing these pictures to Hada’s sister-in-law on the weekend, the information center says.

Hada is a writer and former bookstore owner. He was jailed in 1995 after he organized a rally in the provincial capital Hohhot, where dozens attended.