Supermarket firms Tesco and Asda have said they are looking into allegations of worker abuse at garment factories used by their suppliers in Bangladesh.
The textile industry is a large employer in Bangladesh
The retailers' comments came after a Guardian investigation claimed that workers making clothes were paid as little as four pence an hour.
Tesco said it had done all it could to ensure "high standards and good conditions" in the country.
Asda said any abuse was "unacceptable" and it may audit its factories.
In its report, the Guardian claims that garment workers are regularly forced to work 80 hours a week in factories where conditions are often violent, and where staff do not have access to trade unions.
Allegations of abuse of workers in South Asia's textile industry are nothing new.
Charities such as War on Want have campaigned for years to improve the pay and conditions for garment workers in Bangladesh and last year wrote a report based on interviews with 60 workers from six garment factories.
The group claimed that retailers could only sell their clothes at very low prices by pressuring suppliers in developing economies to keep costs down.
As a result, suppliers in countries such as Bangladesh have had to drive down wages and extend working hours, as there is stiff competition for the retailers' business from other developing nations such as China. .
Asda told the Guardian that: "We find abuse of any kind unacceptable."
The retailer blamed the problem on the fact that one of their approved suppliers was outsourcing its work to another factory without its knowledge and against its wishes.
Tesco said it had taken steps to improve working conditions.
"We have stuck by Bangladesh, continued to invest in modern factories and done all we can to ensure that high standards and good conditions are maintained," the UK's largest supermarket firm said in a statement.
The company added that in many ways it would be easier for them to stop sourcing garments "in countries that have economic and social problems which are beyond the capabilities of any organisation working alone to fix".
However, the company added that it would not be "right for the people of Bangladesh or what our customers would expect us to do".
Tesco said it had just completed unannounced audits at all of its 48 sites in Bangladesh.