The first gay couple to marry in Malawi face a humiliating medical examination aimed at proving they have had sexual relations, it emerged today.

Tiwonge Chimbalanga and Steven Monjeza could be sentenced to 14 years in prison if found guilty of "unnatural practices between males".

Gay rights campaigners reacted angrily to the men's treatment and warned that a renewed trend of homophobia was sweeping Africa.

Chimbalanga, 20, and 26-year-old Monjeza made history when they committed to marriage at a symbolic ceremony last weekend – the first same-sex couple to do so in the southern African state, in which homosexual acts are illegal.

Two days later, they were arrested at their home. Chimbalanga, wearing a women's blouse, and Monjeza appeared in court in the city of Blantyre to answer three charges of unnatural practices between males and gross indecency.

The court was reportedly packed, with some spectators offering support and congratulations while others yelled insults.

The state prosecutor argued that the men had been living together as a married couple since August, and applied for them to be sent to hospital to prove they have had sex together.

The couple deny consummating their relationship, their lawyer, Noel Supedi, said.

"Up to the time of their arrests, there is no evidence they have had sexual intercourse," Supedi told reporters.

"Unless they give their consent to the medical examination, we will protest. According to the constitution, only when someone gives their consent can they be subject to experimentation – and this is tantamount to experimentation."

He added: "It's difficult to say what the couple think about it, but my own assessment is they should not undergo a medical examination because it would be a humiliating invasion of their privacy.

"It would only be serving the interests of the state. It would infringe their rights."

The men have denied all the charges against them, but remain in custody pending an application for bail on Monday.

Supedi said he had not yet had opportunity to ask them why they had chosen to make such a public stand.

"I think maybe they regret it," he added. "Chimbalanga was happy and normal in court, but Monjeza seemed very worried and was crying. Perhaps he did not know it would go this way."

As he was sent back to prison, Monjeza hinted to reporters at the court that he might consider calling off the marriage.

"I am sad I am going back to Chichiri prison," he said. "The conditions are terrible there. People are exaggerating this thing. I may just as well dissolve this marriage."

Chimbalanga refused to speak to journalists, other than to accuse them of writing "stupid" things.

The fight against HIV is slowly changing the official position, however. The government made its first public comment on homosexuality in September, when it said gay rights needed to be recognised to help fight HIV and Aids.

The Centre for the Development of People (CEDEP), a local human rights organisation, has estimated that 25% of the country's gay men are HIV positive.

Malawi's health ministry says the overall rate of HIV infection is 12%.

Cary Alan Johnson, the executive director of the International Gay and Lesbian Human Rights Commission, said: "Malawians have fought long and hard for a working democracy – rights to expression, association, assembly and non-discrimination are part of a truly democratic tradition.

"We hope that the police and the courts will recognise that these men have committed no crime and deserve neither to be detained nor to be the subject of ridicule by the media."

• This article was amended on 1 March 2010 to delete a paragraph on

a separate Malawian dispute. The paragraph incorrectly suggested that Nick Henderson, a London-based vicar, had been sent by the Anglican church to be Bishop of Lake Malawi. In fact, he had been chosen in 2005 by members of the diocese.