Bent coppers are on everyone's mind at the moment as Line of Duty reaches its finale.
But there is one real life Ted Hastings who has spent more than a decade tackling dodgy detectives - just like the AC12 chief played by Adrian Dunbar in the BBC drama.
John McKeon heads the anti-corruption unit at the National Crime Agency, after rising through the ranks of Merseyside Police, reports The Mirror.
He said: “Line of Duty is like a distilled version of 13 years looking at anti-corruption.
“Someone jokingly called me the real-life Ted Hastings, which I don't mind.
"But if I find myself saying, 'Mother of God' more than once in a day I'll be worried."
John joined Merseyside Police 32 years ago and rose to the rank of Detective Inspector.
He watched as the force was mired in corruption when the deputy head of the Merseyside drugs squad, Elmore "Elly" Davies, was jailed for five years in 1998 for his part in a plot to undermine the trial of a man accused of firearms offences.
With Mike Ahearne, better-known as Warrior from TV's Gladiators, he was convicted of trying to subvert the trial of Philip Glennon Jnr.
Glennon Jnr, an associate of drugs baron Curtis Warren, was convicted of having ammunition with the intent to endanger life.
John said: "As a result of that Merseyside Police became a pioneer in anti-corruption work.
"I grew up with it all through all that. It always held an interest for me because my background had always been serious and organised crime."
In 2008 he became the deputy head of the force's anti-corruption unit, and took the top job in 2011.
His first operation led to the conviction of PC Sayful Islam for helping transport cannabis.
It's believed Islam was planted in Merseyside Police by an organised crime group – like Line of Duty baddie Ryan Pilkington – who was killed in a shoot-out after it emerged he was a bent.
John also worked on the case of PC Paul Fletcher, a distinguished officer jailed for seven-and-a-half years for feeding information to criminals.
John said: "There were significant cases where criminal groups infiltrated law enforcement."
In 2016, he took up a role as the Head of the National Crime Agency's Anti Corruption Unit.
Two years later his unit snared corrupt UK border official Simon Pellett who was arrested by French police with 10 handguns, ammunition, heroin and cocaine in October 2017.
John, now 56, said: "He was timebomb of corruption – he displayed all the signals."
An NCA report last year identified organised criminals as "the most significant external corruption threat to UK law enforcement."
But John said: "It's a tiny percentage of people who end up corrupt."
