The official chocolate sold in connection with the Swedish Crown Princess's wedding is produced with the help of child labour, a Swedish public radio report charges

The criticism came a day before Sweden's future queen, Crown Princess Victoria, 32, is set to marry her former personal trainer, 36-year-old Daniel Westling, in one of the largest public celebrations ever organised in Sweden.

The radio report said Swedish chocolate maker Cloetta used cocoa collected "in a large part by West African children under harsh working conditions" in its products.

Cloetta spokeswoman Christina Bjoerck told AFP the company bought cocoa from producers in Germany and the Netherlands, who in turn purchased cocoa from cooperatives or middle-men in West Africa, mostly in Ghana and the Ivory Coast.

"The whole cocoa industry is fully aware of the problem" related to child labour, she said, adding that part of the problem was that many producers were small family operations.

Cloetta launched a line of fair-trade certified products in February, but they do not include the wedding chocolate, which is "unfortunate," Ola Hoeiden of Fairtrade Sweden said.

"We would have gladly seen a fair trade mention (on the wedding chocolate) to make clear child labour had been avoided," he told AFP.

Cloetta is one of the many brands behind the "official wedding series" products approved by the palace, ranging from sweets to glassware and porcelain.

Part of the revenue from the official wedding series product sales will go to the couple's wedding charity, to "support children and young people in Sweden, with the purpose of combatting exclusion and promoting good health," the palace says.