Longtime Chinese human rights campaigner, author and founder of the Laogai Research Foundation, Harry Wu has died. He was 79.

Laogai Human Rights Organization administrator Ann Noonan told The Associated Press that Wu died Tuesday morning while on vacation in Honduras.

Wu was sentenced as a university student to 19 years in China's prison camp system known as laogai, or "reform through labor." After his release, Wu moved to the United States in 1985 but returned frequently to China to conduct research on the labor camp system.

Having become a U.S. citizen, Wu was arrested during a visit to China in 1995 and sentenced to 15 years on espionage charges. He was immediately deported to the U.S. where he continued his work documenting Chinese human rights abuses.