Fifteen years prior to Line Of Duty hitting our screens, a little-known unit of the Metropolitan Police was being secretly set up to crack the cycle of corruption that infiltrated the country’s biggest police force. The unit was CIB3 and its purpose? To expose corrupt police officers and bring them to justice. One of the first targets was former Met Detective Duncan Hanrahan, and with the newly formed CIB3 ready to go, Operation Eden was put into motion.

After the success of Operation Eden, the next target was private investigation firm Southern Investigations, a firm linked to the Daniel Morgan murder. A painstaking and complex undercover investigation produced another successful result for CIB3 and following intelligence from the Ghost Squad, concerns were raised about a branch of the Flying Squad and a massive sting operation was put into place. Operation Brunei and Operation Ethiopia were born.

In the late 1990s, CIB3 carried out one of the most high-profile investigations into a team of hard-drinking road detectives who called themselves the Groovy Gang which became known as Operation Russia. In 1998, the Met Police Chief told a Commons select committee that the force had hundreds of corrupt officers within its ranks but whilst they were not all convicted, the Ghost Squad certainly left its mark.