A very eagle-eyed Line of Duty has spotted what they believe is an important clue about the 'murky past' of one of Jo Davidson's team.
Troubled DCI Jo had already been revealed to have links to the OCG with deceased gang leader Tommy Hunter outed as her blood relative, thanks to the work of AC-12.
While Jo has also had to work with undercover gang member Ryan Pilkington on her team, who was last seen pointing a gun at Kate Fleming.
Now one observant fan of the BBC crime drama believes there is another rotten apple in Jo's team who has yet to be detected.
In the latest twist to season six it was revealed that murdered journalist Gail Vella was looking into the suspicious death of Lawrence Christopher - a young black man killed in police custody in 2003 after being attacked by a gang of white youths.
As AC-12 member Chloe Bishop took Steve Arnott and Ted Hastings through her findings, she revealed a brief look at the gang members involved who she explained were all let off the crime and given anonymity to protect them.
As mug shots of each member flashed up on screen one viewer at home claimed to instantly recognise one of them.
"Seriously has no one else genuinely spotted this? Was the first thing I noticed #LineOfDuty#chrislomax#lawrencechristopher," they tweeted - sharing snaps of the gang alongside Detective Sergeant Chris Lomax.
After putting out the theory that Jo Davidson's right hand man at Hillside Lane Station was a member of the gang responsible for killing Christopher many other fans of the show jumped in with their guesses.
"Yep I spotted that too. Although there are a lot of red herrings. So it’s possible that he isn’t a bad guy," said one.
"Very true. Though it directly connects him to Tommy Hunter’s son. And it gives him a motive for Gail Vella’s murder as he wants to keep his past a secret," speculated another.
"OMG. You could be right. We need a face front pic to be sure," said a third.
Find out what happens next when Line Of Duty returns Sunday night at 9pm on BBC One.