Liu died Monday at a hospital in New Brunswick, N.J., the Los Angeles Times reported.
The son of a railroad worker, Liu taught himself to read English, Russian and Japanese. He joined the Communist Party in 1944 after reading Karl Marx. When the party came to power in 1949, he worked for the China Youth News in Beijing.
Liu's first investigations of corruption in the 1950s brought him exile to agricultural work in the countryside and eight years in a labor camp after the Cultural Revolution.
In 1979, as a reporter for the People's Daily, he resumed his work, exposing corruption in the Communist Party and earning the nickname "Liu the Just."
Liu was a Nieman Fellow at Harvard during the Tiananmen Square massacre in 1989 and never went back to China. His book, "A Higher Kind of Loyalty: A Memoir," was published in 1990.
A friend told the Times Liu's ashes will be returned to China.