Riot police arrested scores of members of the Zimbabwe Congress of Trade Unions (ZCTU) on Wednesday, disrupting a planned march in the latest clampdown by Robert Mugabe's government.
At their first court appearance on Friday, lawyers said the unionists were assaulted "excessively and brutally" during arrest while demanding better pay and access to anti-retroviral HIV/AIDS drugs.
Magistrate Olivia Mariga ordered an investigation into the torture charges, which state prosecutors did not dispute. She also granted bail to all those detained in the capital pending trial on October 3.
Sarudzayi Njerere, defence lawyer, said police beat the group, including ZCTU’s president, Lovemore Matombo, and its secretary-general, Wellington Chibebe, at a Harare police station.
"The accused persons were tortured brutally and severely. Wellington Chibebe has been unable to be here because he has been hospitalised."
Many of the accused limped into the courtroom while several wore arm slings and bandages.
Those granted bail included a freelance television journalist arrested while covering the abortive protest for Reuters. He said he was not assaulted.
The defence said the ZCTU members were initially denied medical attention and forced to wade barefooted through raw sewage in cells condemned as inhumane by the Supreme Court.
Amnesty International, the human rights, group, said it was "gravely concerned" over the torture and over the holding of rights activists and mothers with babies, who were arrested earlier this week and denied access to adequate food and medical care.
It was unclear if similar proceedings had taken place in other urban areas where many unionists were held.
Alec Muchadehama, a defence lawyer, said the ZCTU members would deny state charges of participating in a gathering with the intent to promote public violence and dismissed state lawyers’ assertions that they had threatened state security.
"They were asking for bread-and-butter issues."
The ZCTU says workers have been hardest hit by an economic recession marked by the world's highest rate of inflation as well as shortages of food, fuel and other basic commodities.
The veteran leader, in power since independence from Britain in 1980, denies responsibility for Zimbabwe's economic woes, blaming them on what he calls sabotage by Western powers opposed to his government's seizure of white-owned farms for blacks.