By Jo Fidgen
BBC News, Lusaka
Chansa Kabwela believes the case is political
The news editor of Zambia's largest independent newspaper has gone on trial accused of distributing obscene images.
Chansa Kabwela sent two photographs of a woman giving birth without medical help to the country's vice-president, health minister and rights groups.
She says she was highlighting issues in the healthcare system and calling for an end to a nurses' strike.
But President Rupiah Banda called the pictures pornographic and demanded a police investigation.
The Post's news editor Ms Kabwela did not publish the controversial photographs, but sent copies to a number of prominent people and women's rights groups, along with a letter calling for the strike to be brought to an end.
The defence is arguing that the case rests on the definition of obscenity and so witnesses should have to describe what counts as obscene and arousing.
The first prosecution witness, the senior private secretary to the vice-president who opened the Post's letter, was roundly embarrassed by having to describe arousal.
Critics of the government
The pictures are graphic. They show a woman in the process of giving birth to a baby in the breech position - when the baby's legs come out first.
Its shoulders, legs and arms are visible, but the head has not yet been delivered.
The photos were apparently taken in the grounds of Lusaka's main hospital.
The nurses were on strike and the woman had been turned away from two clinics.
By the time doctors operated, the baby had suffocated.
Ms Kabwela says she was given the photographs by the woman's relatives.
President Banda expressed his outrage at a news conference, calling the photographs pornographic.
Pornography is illegal in Zambia and Ms Kabwela was arrested soon afterwards and charged with distributing obscene material with intent to corrupt public morals.
She faces five years in jail.
In her view, and in the view of campaigners for press freedom, the case is political.
The Post - Zambia's most popular newspaper - has relentlessly pursued the government with allegations of corruption and the president has made no secret of his dislike of the paper.