The Metropolitan Police paid Covert Human Intelligence Sources £1.9m in 2009/10, a small rise from the the £1.86m figure that was paid out in the previous year. The Independent also reported that a further £176k was spent on travel, accommodation and meals for police informant handlers.

Should the police be paying such sums of money to the crimals? Or does it reflect a truly cost-effective method of gathering and acting upon intelligence? The moral dilemma of paying informants to provide information on other criminals is always going to be present but if the alternative is to spend many more hundreds of thousands of pounds on undercover surveillance, then it must remain a crucial tool for modern-day policing.