I am writing this column in one of my favourite London haunts – the Great Court at the British Museum. I’ve just been to see one of the museum’s most famous and controversial exhibits, the Parthenon Sculptures – also known as the Elgin Marbles. These carvings were taken from the Acropolis in Athens more than 200 years ago by the Earl of Elgin. But while there’s a predictably long-running argument over whether the carvings should ever have been removed, the trade in antiquities remains very much alive today.

This trade is almost inevitable. In a poor country, such as Mali or Cambodia, foreigners are likely to be willing to pay more for artefacts than the locals would.