Chinese authorities sent a leader of an underground church in Henan province to two years "reeducation" in a labour camp, US-based supporters said.
Zhang Yinan was sentenced by the Re-education Through Labour Commission in Henan Province, said Bob Fu, of the Pennsylvania-based China Aid Association, a non-profit Christian organisation.
"This is an unprecedented charge to a Christian who has been doing nothing but preaching and writing for the church," said Fu, who predicted camp warders would try to force Zhang to renounce his faith.
Zhang and another man, Xiao Biguang, were detained in September in a case thought to be related to the drafting of regulations aimed at coordinating underground churches in China, another group, the Hong Kong-based Information Center for Human Rights and Democracy said.
On October 21, Xiao's wife Gou Qinghui was told her husband had been placed in criminal detention for "overthrowing the state power", a charge that could place him in jail for 10 years or more.
Zhang's family was informed 10 days earlier that the same charge had been brought against him.
China only tolerates religious activity within the framework of so-called "patriotic" associations which the government controls.
Other sects and churches, including the banned Falungong sect, have been severely repressed.