The detective credited with bringing the Kray twins to justice has died at the age of 95.
Former Det Ch Supt Leonard "Nipper" Read arrested notorious east London gangsters Ronnie and Reggie Kray in May 1968, after trailing them for years.
He later wrote two autobiographies of his exploits, and was played by Christopher Eccleston in the 2015 biopic film Legend about the twins.
Mr Read was also a former chairman of British Boxing Board of Control.
He died early on Tuesday morning.
Born in Nottingham in 1925 and raised in the city, Mr Read joined the Metropolitan Police in 1947.
He was part of the team that solved the Great Train Robbery in 1963 and was posted to Scotland Yard's murder squad in 1967
He led the investigation into the gangsters, leading to them both being jailed for murder in 1969.
In a tribute on Twitter, the Metropolitan Police Heritage Centre described Mr Read as "a Met legend".
It added: "His autobiographies hold places of honour in our collections."
Mr Read was also a keen boxer and earned his nickname "Nipper" while training at Grundy Boxing Club.
Frank Warren and everyone at Queensberry Promotions is sad to hear of the passing of former BBBofC Chairman, Leonard ‘Nipper’ Read QPM.— Frank Warren (@frankwarren_tv) April 7, 2020
Nipper was a great man and a good friend. RIP. pic.twitter.com/vWij89SiXy
The British Boxing Board of Control called him a "wonderful servant" to the sport.
"It is with great sadness that the British Boxing Board of Control has learnt of the passing of [our] former chairman," general secretary Robert Smith said.
"Our condolences to Nipper's family at this time."
Boxing promoter Frank Warren said Mr Read was "a great man and a good friend".