A Chinese employee of a Japanese newspaper was detained by police ahead of the 25th anniversary of the 1989 crackdown on the Tiananmen Square pro-democracy protests, the newspaper and family members said.
The Nihon Keizai Shimbun said the family of one of its news assistants in its bureau in the southwestern city of Chongqing was notified of the assistant's detention on suspicion of picking quarrels and provoking troubles.
The family of Xin Jian, a Nikkei news assistant, on Wednesday confirmed that she had been detained - the latest of a string of detentions ahead of the 25th anniversary of the military crackdown that took place on June 4, 1989.
The ruling Communist Party tries to prevent commemorations or public discussion of the crackdown.
Others detained include a human rights lawyer, Pu Zhiqiang, and a prominent journalist, Gao Yu.
Ding Zilin, a founder of the Tiananmen Mothers, which represents families of those killed in the military attack on protesters, has been placed under house arrest.
''The response by the Chinese authorities to the 25th anniversary has been harsher than in previous years, as they persist with trying to wipe the events of 4 June from memory,'' said Salil Shetty, Secretary General of Amnesty International, in a written statement.
Xin was taken away from her Chongqing home on May 13 after police detained Pu and four others who had attended a May 3 commemoration of the 1989 crackdown.
Nikkei said police initially told the news assistant's family that police wanted cooperation in Pu's case.
Xin had assisted Nikkei reporters in interviewing Pu, best known for his successful lobbying for the closure of Chinese labor camps.
Police had used the camps to lock up people for up to four years without due process.
A woman who answered the phone at Xin's home number and said she was her mother confirmed Xin had been detained. She declined to provide further information, saying the phone line was tapped.
''We believe she is innocent,'' the woman said.
Beijing police did not immediately respond to a request for information.
Chinese authorities have warned foreign journalists of ''extreme consequences'' if they report on sensitive issues ahead of the anniversary.