Published reports say Chinese authorities are trying to brainwash an outspoken doctor who urged the government to acknowledge mistakes in the 1989 Tiananmen Square crackdown.

Sources tell foreign reporters in Beijing that Dr. Jiang Yanyong, who has been detained since May, is being forced to undergo what's called "reeducation." The sources indicate he is under 24-hour guard at an undisclosed location, where authorities have threatened to keep him until he changes his mind about the Tiananmen crackdown.

Dr. Jiang wrote a letter urging that the government reclassify the 1989 pro-democracy protests as a patriotic movement, rather than a counter-revolutionary disturbance.

Last year, the 72-year-old Beijing physician was reprimanded after he revealed that some Chinese officials were covering up the real extent of the SARS outbreak.

Some information for this report provided by AFP and Reuters.