The footage was shot at the Pegatron's factories in China, this company manufactures a wide range of devices for other firms, including motherboards, graphics cards, laptops, smartphones, cable modems, game consoles, etc. Full details over here.
It found standards on workers' hours, ID cards, dormitories, work meetings and juvenile workers were being breached at the Pegatron factories.
Apple said it strongly disagreed with the programme's conclusions.
Exhausted workers were filmed falling asleep on their 12-hour shifts at the Pegatron factories on the outskirts of Shanghai.
One undercover reporter, working in a factory making parts for Apple computers, had to work 18 days in a row despite repeated requests for a day off.
Another reporter, whose longest shift was 16 hours, said: "Every time I got back to the dormitories, I wouldn't want to move.
"Even if I was hungry I wouldn't want to get up to eat. I just wanted to lie down and rest. I was unable to sleep at night because of the stress."