Clothing union chiefs on Sunday claimed up to 4,000 textile workers are being forced to work up to 100 hours a week in scores of illegal garment sweatshops around Brisbane.

According to the Textile, Clothing and Footwear Union, machinists and cutters from Asia are being paid as little as A$2.50 an hour with children as young as 10 also forced to work long hours in appalling conditions.

The union's state secretary, Jack Morel, told the Sunday Mail that Queensland was becoming the country’s sweatshop capital due to soaring labour costs in Melbourne and Sydney.

"It's the hidden shame of Brisbane," he told the paper. "Most people would be horrified if they knew this kind of Third World exploitation was going on in their back yard.

"It's a double-edge sword - if we do anything, they will lose their only source of income, but in my industry I can't allow people to be exploited".