A new Channel 4 documentary will follow a police force as it investigates its own officers.
Provisionally titled 'The Real AC 12', cameras will be given unprecedented access to the Professional Standards Department (PSD), including the counter corruption unit, one of the most secretive enclaves of British policing.
Avon and Somerset Police has granted Story Films access to the teams within PSD to show the reality of its work, at a time when the scrutiny of police officers has never been greater.
Episodes will air over three, hour-long instalments.
Channel 4 say: "This series will take viewers into an unknown area of UK policing which can involve counter corruption, covert investigations, surveillance and police stings.
"The most serious cases include officers abusing their positions of power to exploit vulnerable members of the public, passing intelligence to organised criminals and complaints of racial discrimination and excessive use of force. Careers and reputations are on the line with the most serious offenders facing the prospect of years in prison.
"Told from multiple perspectives the series will look at the reality of being an officer under investigation and the personal strain it involves, as well as the experience of the complainants -often vulnerable members of the public- and the PSD investigators themselves as they conduction their operations under conditions of enormous secrecy and unique pressure. "
Supt Simon Wilstead, head of Professional Standards, said: “The public expects all police officers and staff to adhere to the very highest of standards, both in and out of work, and the important work of Professional Standards ensures we meet these expectations to maintain legitimacy in policing.
“We already hold misconduct hearings in public and publicise the outcomes but there’s much more work going on out of the public eye. In the spirit of being as open and transparent as we can be, we hope this documentary will give the public a unique insight into our commitment to maintaining the high standards of policing which are the envy of the world.”
Executive producer at programme makers Story Films, Peter Beard said: “At Story Films we always look to engage audiences in important and compelling stories that are difficult to access and tell.
"This feels like an incredible opportunity to see a side of policing that has remained hidden to most of us but is so important for all of us to understand.”
An air date is to be revealed.