Tie Liu, whose real name is Huang Zerong, was taken away by police and placed under criminal detention at the weekend for "picking quarrels and provoking trouble", said his friend, lawyer Liu Xiaoyuan.
The charge is frequently used to silence those who challenge the ruling party.
Tie -- who turned 81 in May -- has long been a thorn in the side of Communist authorities. As a young journalist critical of Mao Zedong, founding father of the People's Republic, he spent more than 20 years in labour camps before being rehabilitated in 1980.
"His wife believes it's because of an essay he wrote," Liu told AFP, noting that Tie recently penned a piece critical of top Communist Party propaganda official Liu Yunshan.
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The move has been condemned by international rights groups, including the PEN American Centre, which has called for his immediate release.
"The government in Beijing has been trying to repress Tie's ideas for almost 60 years and, even though he's over 80, they have not let up," said Dominic Moran, director of the PEN American Centre's free expression programme.
Liu said that the authorities' targeting of Tie could set a new record.
"Tie Liu was born on May 29, 1933," he wrote on Twitter. "With his detention, he becomes China's oldest person suspected of 'picking quarrels and provoking trouble'."
Tie's detention comes amid a broad crackdown on dissent in the past year and a half since Chinese President Xi Jinping rose to power.
Dozens of journalists, human rights activists, lawyers and others have been targeted.
Last week rights activists Guo Feixiong and Sun Desheng were due to face trial for their part in protests supporting a liberal southern Chinese newspaper. The hearing was postponed after their lawyers boycotted the proceedings.