I'd been told that child labour was endemic in Turkey. But I wasn't prepared for the reality of it. Or the scale of it. One basement workshop was almost entirely staffed with children, many of whom couldn't have been more than seven or eight years old, the very picture of Dickensian misery.

I was in Istanbul investigating allegations that Syrian refugees and children are being exploited by the garment industry. And specifically that many are working on clothes destined for our High Street.

This undercover investigation was unusually tricky. Secret filming is illegal in Turkey and we were halfway through our investigation when a state of emergency was declared in the country. We were routinely stopped and questioned by police. Our secret filming equipment had to be kept out of sight.