Cadet has died in a car crash on the way to a gig at Keele University in Staffordshire.
The rapper from south London, whose real name is Blaine Cameron Johnson, died in the early hours of Saturday morning.
The news of Cadet’s death was confirmed by his family on his official Instagram account.
In a statement to Radio 1 Newsbeat, his management said the 28-year-old was a passenger in a taxi.
Cadet’s cousin Krept – of rap duo Krept and Konan – led the tributes online, saying he was “heartbroken”.
The 28-year-old had been rapping alongside Krept and Konan since he was a teenager.