The reputation of the private investigation industry has taken another turn for the worse this week. News that the detective firm Southern Investigations had placed the former Metropolitan Police Commissioner Lord Stevens under surveillance has been greeted, quite rightly, with indignation. The notion that the most powerful police chief in the land can be spied upon by private eyes – and remain completely unaware that this was happening – throws into stark relief the sheer audacity of private detectives in Britain.

Last July I presented a Radio 4 documentary called Crouching Low, Hidden Camera, about the shadowy world of private investigators. Over a period of some months I intensively researched the industry, speaking to detectives both on and off the record, and even joining a team from an agency called Answers Investigation on a surveillance operation. What I discovered was rather shocking. In Britain, there is no regulatory system for private detectives. Yes, you read that right. Private eyes are free to do as they please. Continue reading on the Telegraph website