International law bans mines from employing workers under 18 but the BBC said undercover cameras filmed several under that age in the Glencore-owned Tilwezembe mining operation.
Ivan Glasenberg, Glencore's chief executive officer, said the company wasn't using child labor to make a profit, the BBC reported Sunday.
The child miners belonged to a group of wildcat miners who "raided our land in 2010 … against all of our authorization," Glasenberg said. "We are pleading with the government to remove the ... miners from our concession."
Glencore stopped mining at the Tilwezembe location in 2008, and said the mine since has been taken over by local workers, who are mining without the company's permission.
The BBC report tracked buses leaving the mine and going to a processing plant owned by one of Glencore's main partners in the DRC. Documents obtained by the BBC indicated some of the copper from the Tilwezembe operation was sent from the processing plant to a Glencore smelter in Zambia.
The broadcaster's investigation also turned up evidence of acid pollution in a river near the Glencore copper refinery in Luilu. A Swiss non-governmental organization said its acidity tests indicated the waste water had a Ph value of 1.9 on a scale in which 1 is pure acid and 7 neutral, the BBC said.
Glencore said the pollution occurred long before it took over the refinery.