A report in the Guardian newspaper revealed that workers in clothing factories who supply Primark, Asda and Tesco are working for a little as 4p an hour for up to 80 hours a week.
Tesco and Asda are investigating the claims that factories in Bangladesh are exploiting the workers who make their clothes.
Asda has announced that it may audit its suppliers. A spokesperson for Primark said that the conditions are of “considerable concern”.
The workers are also said to have been refused access to trade unions, claiming several colleagues had been sacked for trying to organise a union in recent weeks.
Mohammed Lutfor Rahman, a factory owner in Bangladesh, who only supplies to the US and German market, told the Guardian buyers that gave him little choice but to keep wages low:
“Buyers who come to Bangladesh tell us, ‘we are businessmen, we want to make money. If we see cheaper prices in China we will go there’.”
Mr Rahman added:
“I would be the happiest man in the world if I could provide my workers with good money, air conditioning, health benefits. They are like children to me. But if I cannot cover the costs of running a factory, it will close.”
The new allegations echo similar claims of exploitation made last year by charity War on Want.