Nike has pledged to pull out of the factory it uses in Cambodia and the Gap has suspended orders there, following Sunday's BBC Panorama programme, which uncovered the use of child labour by both companies.
The programme investigated the conditions inside sweatshops used by the two companies, focusing particularly on one factory owned by June Textiles Co in Phnom Penh, which produces clothes for both brands. Hidden cameras smuggled inside showed children who appeared to be younger than 15 years old working on the shopfloor, while other employees admitted working seven-day weeks.
Nike's head of corporate communications, Yvonne Iwaniuk, admitted the factory had 'broken our code of conduct on a number of points'.
'We are very concerned about some of the allegations and wish to make it clear that we had already decided to pull out of the factory in December. Nike has also promised to pay for any workers found to be underage, to go to school until they turn 16,' she said. 'We are not being arrogant. We are learning from this.'
Iwaniuk said Nike carries out regular internal and external audits of its 500,00 workers and 700 factories worldwide, most of which are in Asia.
But she said it was not simply a case of one factory slipping through the net, as many children falsify documents to get work.
The Gap said it has suspended orders at the Phnom Penh factory and is refusing to accept products made on the site until it has verified the ages of all workers. It said it would not terminate a factory contract for violations of The Gap's conduct code, though it had done so where a factory refused to implement improvements.
The Panorama investigation is the latest in a series of TV documentaries investigating the conditions of overseas workers, indirectly employed by big brands.
Chocolate makers including Cadbury, Nestle and Mars were named last month by a Channel 4 documentary, which alleged that in the Ivory Coast, the world's largest cocoa producer, 90% of cocoa plantations use slaves.
The Biscuit, Cake, Chocolate and Confectionery Alliance is planning a meeting next week to plan how to investigate the allegations.