A Taiwanese human rights group says the wife of a jailed pro-democracy activist will visit him in prison in China this week.

The Taiwan Association for Human Rights said Lee Ching-yu left Taiwan on Monday to see her husband Lee Ming-che in prison in central China.

Lee Ming-che is serving a five-year prison sentence after being convicted by a Chinese court in November of the vaguely defined charge of "subversion of state power."

Lee was found guilty of subversion for holding online political lectures and helping the families of jailed dissidents in China.

His conviction showed how Beijing's harshest crackdown on human rights in decades has extended beyond the Chinese mainland. Beijing regards self-ruled Taiwan as part of Chinese territory.