An investigation by the BBC’s Panorama programme has claimed that the standards on workers' hours, ID cards, dormitories, work meetings and juvenile workers were being breached at the factories supplying Apple.

Filming on an iPhone 6 production line showed overworked employees falling asleep on their shifts amidst poor working conditions.

Apple said it strongly disagreed with the programme's conclusions. The company said it was a very common practice for workers to nap during breaks, but it would investigate any evidence they were falling asleep while working.

In a statement, Apple said: "We are aware of no other company doing as much as Apple to ensure fair and safe working conditions. We work with suppliers to address shortfalls, and we see continuous and significant improvement, but we know our work is never done."