Shanghai (AsiaNews/Agencies) - Zhang Lin, a pro-democracy leader in Anhui province, was detained as a threat to national security. Relatives do not know where he is being held.
Mr Zhang was stopped by security officials when he tried to pay his respects to the late Zhao Ziyang, former Secretary General of the Chinese Communist Party, said activist Ren Wanding.
"He came to Beijing on January 28 to go to Zhao Ziyang's house, but was not allowed in, so he went back to Anhui on January 29," Mr Ren said.
"After going back to Bengbu he was seized by the police and held for 15 days and his computer taken. Today his wife and friends went to pick him up, but the police said he had been detained for threatening state security and sent to jail."
"His family is very worried," Mr Ren said.
A family friend reached by telephone at Zhang's house in Bengbu in Anhui confirmed they had failed to pick him up.
"It's very strange. We don't know why they are doing this. We went to meet him but were unable to," the friend said. "We don't know where he is."
Mr Zhang was jailed for two years for his role in the 1989 protests. He left for exile in the United States in 1997 but stole back into the mainland in November 1998. He was arrested and sentenced in December to three years of hard labour and re-education for illegal entry.
Zhao Ziyang, who died on January 17 after spending 15 years under house arrest for his opposition to the army crackdown in Tiananmen Square, still haunts the authorities, afraid that his memory might trigger public protests.