A city wide event this June will see teams of amateur sleuths attempting to solve the fictitious slaying of the London twins who controlled the city's underworld in the 60s and became known for their celebrity lfestyle.
Sheffield Murder Mystery Day will be held on June 23 - and teams are being sought to take part.
The twins, were the foremost perpetrators of organised crime in London's East End and with their gang, were involved in armed robberies, arson, protection rackets, assaults and murder - including the deaths of George Cornell and Jack "The Hat" McVitie.
After the efforts of detectives led by Detective Superintendent Leonard "Nipper" Read, the pair were arrested in 1968 and both were sentenced to life imprisonment.
Ronnie remained in Broadmoor Hospital until his death in 1995 while Reggie was released from prison on compassionate grounds in August 2000, eight and a half weeks before his death from cancer.
A spokesman for the event described the set up for mystery day and said: "It was winter 1967 and this wasn't a phone call that Chief Superintendent 'Nipper' Read has ever expected to receive.
"Read was not only shocked, he felt cheated. After years of trying desperately to put Ronnie and Reggie Kray behind bars, the pair had just been found murdered!
"Now in a weird twist of fate, it's up to you and your team of detectives to help solve the mysterious double-murder of the UK's most notorious gangsters - but who would have been brave enough to kill the Krays?
"Can you help 'Nipper' hunt all over town, tracking down virtual witnesses, eliminating suspects and solving challenges in our city-wide, murder-mystery game?"
The real-life Cluedo game will take place across Sheffield city centre between 10am and 1pm and the cost is £30 per team.
On the day, competitors will be competing with hundreds of other players to track down witnesses, eliminate suspects and rule-out murder weapons all across Sheffield.
It's a bit like Cluedo meets Pokemon Go - but will your team work out whodunit?
To play, you'll need:
* A team of detectives (at least 2 but up to 6 players per team)
* Access to a Smartphone: Android (Version 5.1 or above) or iPhone (Model 5s or above)
* A good pair of walking shoes
Gangster and glamour fancy dress is optional.
Depending on how good a detective team you are, the event will last anywhere between one and four hours - but the average squad of detectives take around 2 hours 20 minutes to solve the crime.
Further details and tickets are available HERE