LINE Of Duty fans were left baffled tonight by the new series' cop jargon with many confusing CHIS for a crude word.
The acronym, which stands for Covert Human Intelligence Sources, was used frequently as detectives delved into another murder mystery.
Twitter was rife with viewers asking what it stood for and "jizz" was soon trending on the site as many thought they were hearing the slang word for semen.
The confusion was so widespread the BBC voiceover took it upon herself to clarify the acronym as the end credits rolled.
One viewer joked: " new drinking game. Drink every time someone on Line of Duty says chis."
Another posted: "everyone hearing 'chis' and just having to go along with it ."
A third wrote: "why am I hearing Jizz instead of CHIS?!"
Detective Chief Inspector Joanne Davidson is into the murder of journalist Gail Vella, who died from a gunshot wound to the head.
After the arrest of suspect Terry Boyle, who has learning difficulties, Davidson demanded a colleague give up the name of his CHIS, who she believed could have vital information.
These are informants who prevent the worst types of crimes — terrorism, drug dealing, gun crime and child sexual exploitation.
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However, he refused in order to protect their safety and identity, much to her dismay.
It was later revealed the CHIS was a young man who, after his information led to a raid taking place, was thrown from the top of a building — probably by the criminals.
Boyle was bailed after his interrogation, with not enough evidence linking him to the crime to warrant a charge.
It emerged the fingerprints of violent criminal Carl Banks were all over Boyle's flat making him a person of interest.
DI Kate Fleming slyly leaked his name to DS Steve Arnott, who in turn told AC-12 chief Ted Hastings, and the anti-corruption unit will now discreetly try and track the con down.