Jestina Mukoko's lawyer said the money would not make up for all she had suffered
Nine Zimbabwean human rights activists and others tortured in custody are suing government officials for $510,000 (£322,000), their lawyer has said.
Jestina Mukoko and eight others are suing two cabinet ministers and various police officers.
The Supreme Court on Monday ordered that terrorism charges against her be dropped because she had been tortured.
Ms Mukoko's lawyers said she had been subjected to simulated drowning, locked in a freezer and beaten.
She was accused of taking part in a plot to topple President Robert Mugabe, which she strongly denied.
Critics say the charges were fabricated in an attempt to silence opponents of Mr Mugabe's Zanu-PF party.
Analysts say the dropping of the charges against Ms Mukoko and nine others could ease tensions in Zimbabwe's power-sharing government.
At least three others are still facing trial on the same charges.
Police spokesman Wayne Bvudzijena told the AP news agency that they could not be held responsible for what had happened to Ms Mukoko.
Correspondents say it is more likely that members of the feared Central Intelligence Organisation were behind the torture.
Many of the detained were supporters of Prime Minister Morgan Tsvangirai
"Jestina Mukuko is suing the state agents, minister of defence, minister of home affairs, the police officers involved in some of the papers the state filed," her lawyer Harrison Nkomo told the BBC's Focus on Africa programme
"She's basically suing for torture and unlawful detention and also to recover medical and legal expenses that she incurred as a direct result of the illegal activities that were perpetrated upon her by the state security agents."
He added that the money would not make up for everything she had suffered.
Meanwhile, Zimbabwe Lawyers For Human Rights director Irene Petras said Attorney-General Johannes Tomana should resign over his "unethical and partisan" conduct during the case.
He denied the charges and told AP that his officers had behaved professionally.
Ms Mukoko, who had been free on bail since May, disappeared from her home in early December 2008 and was not heard from for three weeks.
The government denied holding her, but at the end of the month she appeared in court facing terrorism charges.
At the end of 2008 dozens of activists claimed they had been abducted by the security services.
Some of them were freed after short spells in detention and others were charged.
Many of those detained were supporters of Prime Minister Morgan Tsvangirai's Movement for Democratic Change (MDC).
Their detention caused huge tension between Zanu-PF and the MDC, who signed a power-sharing agreement last year.
Mr Tsvangirai spoke out on the issue earlier in the year, saying Ms Mukoko's case undermined the power-sharing deal.
Donors are reluctant to resume aid flows to Zimbabwe because of allegations of continued human rights abuses in the country.