Prosecutors today charged former Zimbabwean newscaster Jestina Mukoko and nine other opposition activists with plotting to overthrow President Robert Mugabe's government.
If found guilty the activists could face the death penalty, lawyers said.
Mukoko, the most prominent activist, head of the Zimbabwe Peace Project, had been missing for three weeks will she appeared in court today accused of plotting to overthrow President Robert Mugabe.
Zimbabwe police had denied holding Jestina Mukoko, who had not been seen since being taken from her home on 3 December, the day activists held nationwide protests against the country's deepening economic and health crises.
Ms Mukoko appeared days after opposition leader Morgan Tsvangirai said he would withdraw from talks on implementing a power sharing deal unless at least 42 missing activists and opposition officials were released or charged.
Mugabe has also faced increased international pressure, with the United States and Britain saying they would not back a unity government if he remained president, and Nobel Peace Prize winner Desmond Tutu saying the world must use the threat of force to oust Mugabe.
Charging Ms Mukoko, the respected head of a group known as the Zimbabwe Peace Project, in a plot already widely dismissed as a fabrication is a sign Mugabe is not prepared to back down.
The Herald, the state-run daily, said Ms Mukoko and nine activists of Mr Tsvangirai's Movement for Democratic Change would be charged with attempting to recruit fighters to overthrow President Robert Mugabe. The Herald quoted police as saying the MDC was training fighters in Botswana.
Annah Moyo, a Johannesburg-based Zimbabwean human rights lawyer, said the charges were "trumped up," and could be used by the Mugabe regime as an excuse to declare a state of emergency and withdraw from power sharing talks.
Mugabe's government was "desperate to do what ever it can to try to hold onto power," he said.
Shortly before Mukoko was taken to court, human rights lawyers said they had been visiting police stations and checking arrest records, and had managed to locate 14 activists who had disappeared in recent weeks.
"It is our strong belief that more individuals than those disclosed to lawyers are being held in those police stations, as well as others which have not yet been visited," the lawyers said. "It is also our belief that there may be more abducted persons than those currently confirmed."
Leading Zimbabwean human rights lawyer Beatrice Mtetwa said lawyers received "no co-operation at all" from police, and were ejected from the main police station in Harare, but visited small police stations across the city. All those found, including a mother held with her child, were denied food and medicine from outside the jails and access to legal advice.