Amnesty International has released a secretly-shot film from Zimbabwe, showing what it says is the squalid aftermath of Harare's slum clearances.
Some 2,000 people were believed to be living at the makeshift camp
The clearances have left about 700,000 people without their homes or livelihoods, according to UN estimates.
The human rights group said its film showed people made homeless and then dumped at an informal site.
The images, shot in August, depict a makeshift camp and people queuing up for water at the site near Harare.
Amnesty said people there had to cope with shortages of food and clean water.
The site may have housed up to 2,000 people, it said.
But the organisation said it feared the problem could be widespread, urging the government to say whether other areas like the site shown on the film existed in other parts of the country.
The government in Zimbabwe describes its drive as an urban renewal campaign designed to cut crime and curb illegal development.
It says last month's UN report - which said a total of 2.4m people had been affected in some way - is biased and exaggerated.
Amnesty said the film was shot at Hopley Farm on the outskirts of Harare on 4 August and then smuggled out of the country.
It said the images showed people who lost their homes during Operation Murambatsvina (Drive Out Trash) and who were initially taken to the so-called transit camps.
But the organisation said that such camps in Harare and also Bulawayo were closed following the damning UN report.
"The people who had been in those transit camps were taken under cover of darkness and dumped at various rural areas in the country," Amnesty International researcher Audrey Gaughran said.
"They were left in most cases with no shelter, no food, no access to sanitation and little or no access to clean water.
"Rather than confront the massive humanitarian crisis that its actions have created, the government of Zimbabwe is compounding suffering and human rights violations by attempting to hide the most visible signs of internal displacement," she added.
Ms Gaughran said that since the footage was shot, aid groups had been able to persuade the government to grant them access to the Hopley Farm site.