Tinashe Mugwira, 15, left home in January this year and walked the 50km to Shurugwi in search of work at the mines in the mineral belt known as the Great Dyke, where gold, chrome and nickel are found.
"I had always heard that these Chinese were employing young children for as long as they can work on the mines, so I decided to come here when I stopped going to school after my father fell ill and my mother could not raise money for food," a skinny Mugwira told IRIN.
Chinese mining companies started investing in the area after locally owned mining firms went bankrupt due to the global recession. Child rights activists say the use of child labour is becoming "common practice" in many of the country's mines.
Mugwira said he was one of scores of children working on the opencast mine - ferrying chrome ore in buckets and wheelbarrows - with no formal contracts, protective clothing or medical benefits.
"I get US$10 for every ton I fetch and it takes me about three days to do so. We work from sunrise to sunset together with the adults and are treated the same, but the job is so hard," he said.
Mugwira has been bedridden three times since he began working at the mine, suffering from severe coughing and headaches, but has never received medical treatment and was unable to say what his medical condition was. He lives in a squatter settlement at the foot of the nearby Boterekwa escarpment, with other children and their adult colleagues, many of whom work as illegal gold-miners.
A friend from school working with him on the chrome mine was recently taken to Shurugwi hospital by his older brother, an illegal gold miner, after falling ill. He died of respiratory complications shortly after being admitted.
"It is risky working on these mines but I have no choice. I am the [oldest] in our family and my brothers and sister will die of hunger if I go back home without money," said Mugwira.
Elfas Shangwa, chairman of the Harare-based NGO New Hope Foundation, which campaigns for the rights of children, said: "Poverty is the main cause behind this prevalent practice of child labour at mines and in other sectors of the economy."
An IRIN correspondent visited two mines in the Shurugwi area and witnessed about 17 children working. Most were working on a temporary basis. According to a mine worker who declined to be identified, the use of minors was not being practised by established mining companies, as checks were carried out, but was occuring at smaller mines.
"For a long time, we have been receiving so many reports of child labour on mines throughout the country and intend to carry out our own investigations. Unfortunately, when we report the cases to the police, they tell us they can hardly do anything because Zimbabwe does not have explicit laws on child labour," Shangwa told IRIN.
Zimbabwe is a signatory to the UN Convention on the Rights of the Child and the International Labour Organization (ILO) anti-child labour convention, and Shangwa said his organization was lobbying government to adopt policies discouraging child labour practices.
In Mazowe, a farming district in Mashonaland Central Province, about 70km northeast of Harare, businessmen who have recently acquired small mining concessions use children to mine gold ore and then load it on to trucks.
"The issue of child labour is neither here nor there," Isdore Rukweza, one of the businessmen who has secured mining concessions, told IRIN. "If these children don't come and work for us, their families will have no money to send them to school or buy food."
An activist with a locally-based NGO, Coalition Against Child Labour in Zimbabwe, who declined to be identified, told IRIN the group was embarking on a nationwide survey of child labour practices with other child rights organizations.
"We are aware that children are working long hours in unhygienic conditions for small wages. In some of these cases, adults are shunning the jobs because the employers pay very little," the activist said.
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