It was a confrontation that marked the culmination of a BBC investigation that had begun 51 days earlier - hours after five people, including a seven-year-old girl named Sara, had died in the sea off northern France. She had suffocated beneath a crush of bodies inside an inflatable boat.

That investigation had taken the reporters from the informal migrant camps around Calais and Boulogne, to a French police unit in Lille, to a market town in Essex, to the Belgian port of Antwerp, Berlin, and finally to Luxembourg and a three-day stakeout at the gates of the country’s migrant reception centre.

Eventually, a man was identified as a the smuggler who had been paid to organize Sara and her family’s dangerous voyage to England.

After the confrontation, the investigators informed the French and British police about their findings.