A senior UN official recently described as "unacceptable" the alleged forced labour of indigenous people by landowners in Bolivia. The BBC's Andres Schipani reports on the contentious issue of "slavery" from the eastern province of Santa Cruz.
Teresa Barrio, pictured with her granddaughter, calls herself a slave
Teresa Barrio was born on a patch of scrub on a Bolivian plantation. This is where she has lived and worked. This is where she expects to die. But she has no affection for this place.
The 65-year-old grandmother knows little of other people's lives but she knows her own has been harsh: toiling in fields for a pittance, sleeping in a mud hut, losing sight in one eye and losing five of seven children to disease.
There is no cash in the pockets of her ragged skirt, nor, she says, does she feel free to leave the vast farm where she has worked hard all her life.
"All my life I've been here and at the end of it I have nothing and have nowhere else to go," she says.
Her hamlet of 13 Guarani families - all workers on the plantations near the town of Camiri in Alto Parapeti region in the eastern province of Santa Cruz - built a school but ranchers destroyed it, she says.
"They didn't want us to learn, they want things to be like they always have been," Teresa's granddaughter, Deisy, says.
Beside the ruins is the replacement school - five desks beneath a blue tarpaulin draped from an algarroba tree.
Over the past two years, Bolivia's government and several indigenous groups, have been giving a controversial name to Teresa's type of existence - slavery.
They and some international organisations say conditions are still akin to bonded labour, making these peasants the de facto property of rich landowners in one of South America's poorest countries.
Accusations of forced labour have circulated for decades, with little result.
"We are very scandalised by what we've seen
We have seen indigenous people, the original owners of the land, who are now in a situation of landlessness, forced labour, servitude and extreme poverty," Victoria Tauli-Corpuz, head of the UN Permanent Forum on Indigenous Issues, told reporters in La Paz.
Between 30 April and 5 May, Ms Tauli-Corpuz led a mission to investigate the situation of forced labour amongst the Guarani people in the eastern lowlands of Bolivia, a region known as the Chaco.
"This is a relationship of strong servitude that condemns these people to poverty and dependency on the landlords," says Alejandro Almaraz, Bolivia's deputy land minister.
'Workers, not slaves'
The system hinges on the creation of debt that people have little chance of paying off. Workers are given cash and food, which is then docked from the average daily wage of $2 (£1.30).
"Some have debts owed by their fathers," Wilson Changaray, a Guarani leader, says in the dusty town of Camiri.
Mr Morales has strong support from Bolivia's indigenous groups
Landowners and some opposition politicians say the government's criticisms are a cynical ploy by an "authoritarian" president to grab land and have more control.
"The idea that there is slavery here is absurd
Offering loans and selling food is not a debt trap but a favour because there are few banks and shops in the region," says Eliane Capobianco of the rancher's association Fegasacruz, in the eastern city of Santa Cruz, the opposition heartland.
"The fact that many workers ask employers to be their children's godfathers is evidence of admiration not of dependency. These people are workers, not slaves," she adds.
Yet, over the past year some landowners have blocked government inspectors, sometimes violently. That has only hardened suspicions that some ranchers have something to hide.
The Guaranis' plight was compounded in 1892 when Bolivian soldiers took away their remaining land and forced them to work on landlords' estates. Illiteracy and a lack of identity documents have left later generations dependent on the ranchers.
Evo Morales' victory in the presidential elections more than three years ago offered the prospect of change for Bolivia's indigenous people.
And that prospect came closer in January, when he succeeded in changing the constitution that gives sweeping rights to Bolivia's 36 indigenous groups in the areas of government, the judiciary and landholdings.
It also allows agrarian land reform to take place by limiting the size of rural landholdings in future sales. Supporters say the new constitution will help roll back 500 years of submission of indigenous peoples.
But the situation seems little changed in Alto Parapeti, in the Bolivian Chaco, a place some Bolivians call "a land lost to God". Here the bondage system remains common and the presence of the state is weak.
"We find this situation of domination and violent rule of the landlords over the indigenous people unacceptable
we think this is a gross violation of the basic political, social, economic and cultural rights [of the Guarani]," Ms Tauli-Corpuz said.
Mr Morales has been pushing to end this. In March, he handed over thousands of hectares of land seized from large-scale owners to indigenous farmers.
Yet Teresa Barrio, the near-blind grandmother, still calls herself a "slave". Her ancestors worked and died on estates around hers.
"The owners exploit us, they always do whatever they want," she says, sighing.