A prominent Christian human rights attorney has gone missing for a second time in China.

Gao Zhisheng was last seen in March after a 13-month disappearance at the hands of the Chinese government.

Zhisheng's friends, however, say he failed to return to Beijing April 20, following a week-long visit with family in western China.

Human rights watchers believe Chinese security agents allowed Zhisheng to contact relatives to prove that he is still alive. Now, he is once again missing and presumed to still be in custody of the government.

Forbes.com columnist Gordon Chang lived in China for two decades and told CBN News Zhisheng's disappearance is part of a larger crackdown against attorneys in China.

Click play to watch his comments.

For more on the human rights campaign to free Gao Zhisheng click here.