China released an American-educated democracy activist three years after he was arrested for sneaking back into the country to help an opposition party, the government-run Xinhua News Agency said.

Wang Ce was freed before the end of his four-year sentence because of good behavior, Xinhua said. It said he left China Sunday for an undisclosed location.

Wang, 52, left China in 1984 to earn a doctorate in political science at the University of Hawaii. He settled in Spain and led a group of Chinese exiles, the Freedom and Democracy Party.

Wang secretly crossed into China from Vietnam in October 1998 after authorities refused to renew his passport.

A month later, he met with Wang Youcai, an organizer of the banned China Democracy Party. The two are not related.

Both were arrested soon after. Wang Ce was sentenced in March 1999 to four years in prison for entering the country illegally and financing subversive activities by lending Wang Youcai $1,000.

Wang Youcai was sentenced to 11 years in prison as part of an aggressive crackdown on the party.

Wang Ce's wife had petitioned U.S. officials for help in securing her husband's release and improving what she called harsh prison conditions in the Zhejiang province.

Officials in Zhejiang refused to comment. The U.S. Embassy in Beijing said it hadn't heard of his release.