Commodities trader Glencore has denied it employs under-18s working at a copper mine in the Democratic Republic of Congo, saying any mining at the mothballed site is without its authority.
The BBC's Panorama current affairs show, due to be broadcast on Monday, said it had footage of youngsters under the age of 18 working at a mine where Glencore owns a licence to operate.
The company, which floated last year after four decades of closely guarded privacy, said it stopped work at the mine in 2008.
Glencore's chief executive Ivan Glasenberg said in comments released by the BBC and due to be screened on the programme that the child miners were working "against all of our authorisation.".
Miners filmed by the BBC at the Tilwezembe mine were part of a group of artisanal miners who took over the area in 2010, Glasenberg said.
The company says it plans to resume mining at the site at some point in the future and that in the meantime it is in talks with the government on how best to handle what it has called an invasion by artisanal miners.
"We definitely do not profit from child labour in any part of the world. This is adhered to strictly," Glasenberg told the programme.
BBC Panorama, which filmed the programme in the south east of the DRC in February, has called the programme "Billionaires Behaving Badly?" and on its website said Glencore stands accused of reckless greed.
Glencore also denied any dealings with paramilitaries in Colombia after the BBC said it had seen papers relating to a land deal between a Glencore subsidiary and suspected associates of people who had seized the land seven years earlier, killing 10.
Glencore, which never ended up owning the land, said its involvement had been at the behest of then President Alvaro Uribe, as part of a resettlement programme.
The broadcaster also said Glencore was responsible for environmental damage in the DRC. It accused Glencore of having pumped acid used in mining into a local river.
Glasenberg, who owns 15.8% of Glencore and has a net worth of $7.3 billion according to Forbes, said Glencore had inherited the acid problem when it took control of operations at a refinery in 2009 and had since worked to put in place facilities to end the discharge.
Glencore said that in the last few weeks it had completed the project to end the release of acid into the river.
Shares in Glencore, which is in the process of trying to buy Anglo-Swiss miner Xstrata for $41 billion, traded up 0.8% to 402.8 pence at 1449 GMT, outperforming the European mining index which was 0.1% higher.
