Ellen Chadehama and Ignatius Mhambi were arrested last week accused of possessing pornographic material and insulting president Robert Mugabe.
Their employer, Gays and Lesbians of Zimbabwe (Galz), said the two were assaulted by police while in custody.
They were also made to bend their knees into a sitting position with their arms outstretched for long periods and struck with bottles when they weakened and fell, according to their defence attorney, David Hofisi.
Nelson Chamisa, a government minister and spokesman for the Movement for Democratic Change, condemned the alleged abuse: "Ill treatment or inhumane handling of any human being for any reason goes against our philosophy. We do not believe harassment is the best way of doing business. It flies in the face of the democratic order."
Chadehama and Mhambi were arrested last Friday for allegedly possessing photographs of gay sex and posting a letter in their office from former San Francisco mayor Willie Lewis Brown criticising Mugabe's opposition to homosexuality. Under sweeping security laws it is an offence "to undermine the authority of the president".
Magistrate Munamate Mutevedzi yesterday released the two on bail of $200 each until a trial set for 10 June, where they will face penalties of imprisonment or a fine.
Mutevedzi said provisions of Zimbabwe law on both allegations did not take into account the sexuality of suspected offenders.
Galz said Chadehama, 34, the administrator of Galz, and Mhambi, 38, an accountant, were married with children.
Homosexuality is illegal in Zimbabwe but arrests are rare and Galz operates openly. The public statements of politicians give cold comfort, however.
Mugabe, 86, has described same sex partners as "lower than dogs and pigs". Morgan Tsvangirai, the prime minister, has said: "Women make up 52% of the population … there are more women than men, so why should men be proposing to men?"
The case is the latest in a series of flashpoints raising fears that gay rights are imperilled across Africa. Last week in Malawi a judge sentenced a gay couple to a maximum 14 years in prison with hard labour after the men made a public commitment to marriage.
That decision was condemned by South African president Jacob Zuma yesterday in a rare rebuke to a fellow African nation.
"We have condemned the action taken to arrest people in terms of our constitution," Zuma told parliament in South Africa, where same-sex marriages are legally recognised. "We need to persuade, we need to make people understand, we need to move with them. We have never adopted a confrontational stance on matters."
Phumi Mtetwa, director of the Lesbian and Gay Equality Project in South Africa, said: "The torture and harassment of the Galz comrades and the raid of the offices expresses Zimbabwe's Zanu-PF government's old tactics of dehumanising LGBTI people and Mugabe's allies scoring political points by persecuting those who struggle for rights to equality.
"These struggles have to be seen in light of the increasing public homophobia on the continent – Uganda, Rwanda, Malawi and even South Africa, to mention a few. The South African government has a constitutional obligation to challenge its counterparts to defend the human rights of LGBTI people on the continent."