The Co-operative Group has denied that a BBC probe into child slave labour at one of its suppliers prompted it to broaden its cocoa supply base.

The Panorama investigation, broadcast last month, claimed to have found evidence of human trafficking and child slave labour at Fairtrade cocoa co-op Kuapa Kokoo, Ghana, which owns 45% of chocolate supplier Divine. Last year, Kuapa Kokoo suspended seven of its 33 cocoa farming communities after they were found to be using child labour, the investigation claimed.

Although The Co-op Group was not mentioned in the programme, the society has since split its cocoa supply base so Divine will account for about 30% of its Fairtrade block chocolate sales, from 100% before. The rest will come from ICAM, a Fairtrade supplier using cocoa from the Dominican Republic.

"The decision to broaden our supply base is in no way connected to the programme," a spokeswoman said. "The reason for splitting the business is that it makes commercial sense." It was part of the relaunch of the society's own-label Fairtrade block chocolate range, which will begin next month, she added.