Beyoncé seamstresses 'paid slave wages'
Beyoncé range of women's sportswear is allegedly made using sweatshop labourers who earn as little as $8.50 (R127.50) a day.
The US pop star's Ivy Park gym gear is sold by Top Shop.
The Sun on Sunday reported the clothing range is made by Sri Lankan seamstresses.
Workers are paid more than the legal minimum, but campaigners described the labour as a "form of sweatshop slavery".
Top Shop, which has shops in South Africa, also claimed that the range will "empower women through sport".
One machinist told the tabloid: "When they talk about women and empowerment this is just for the foreigners. They want them to think everything is okay."
A seamstress told the tabloid she earned 18500 rupees a month (R2610), which is about half the Sri Lankan average wage, for a nine- hour shift, five days a week.
Beyoncé said at the launch: "My goal with Ivy Park is to push the boundaries of athletic wear and to support and inspire women who understand that beauty is more than your physical appearance.
"True beauty is in the health of our minds, hearts and bodies."