The International Labour Organization said Thursday it was investigating a new law in Bolivia that allows children as young as 10 to work, amid fears it breached global rules.
"The ILO is still looking into the provisions of the new law," the UN labour agency's spokesman Hans von Rohland told AFP.
"But there are already concerns that the law could amount to a reduction of the minimum age for work below the minima set in the ILO Conventions that Bolivia has ratified," he said.
Bolivia's previous labour code permitted no exceptions to a minimum age of 14, which ILO rules allow developing countries to adopt instead of the global limit of 15.
The new law was approved last week by the parliament of Bolivia, whose left-wing President Evo Morales is a former subsistence farmer and trade union activist.
While it leaves the limit of 14 in place, it allows exceptions when specific legal criteria have been met, taking the age to as low as 10.
The legal limit of 14 had come under fire from critics, including youthful trade unionists, who agued that Bolivians work from an early age out of necessity. Many of the youngsters are employed work in agriculture or as street hawkers.
The ILO's labour convention also says that children between the ages of 13-15 may do light work as long as it does not threaten their health or hinder their education, and that developing countries can cut that to 12-14 years.
Bolivia's lawmakers passed the measure by consensus, requiring employers to respect certain criteria in order to ensure the physical and mental health of employed children, and prevent child exploitation.
The factors include a voluntary decision from the child to work, consent from the parent or guardian and permission from the public ombudsman.
The ILO warned of potential loopholes, however.
"The law could also fail to protect the rights of children working in agriculture on their family farm," said von Rohland.
"In line with ILO Conventions on child labour, those children should enjoy the same right to be protected against hazardous work as other children working for a non-family employer," he added.
Bolivian officials argue that by reducing the legal limit, they hope to eradicate extreme poverty, a key cause of child labour, by 2025.