The 28-year-old music star, was a passenger in a taxi early this morning when it collided with a van in Betley, Staffordshire.
He died at the scene, while the two drivers were taken to hospital with serious injuries.
A family statement shared on his Instagram page read: 'We the family of Blaine Cameron Johnson known as Cadet (Underrated Legend) would like to share the sad news that during the early hours of 9th February 2019 he passed away as a passenger in a taxi, en route to a performance.
"Right now we the family appreciate your patience and will share with you any information as and when we can. Thanks for your support in advance. Love The Johnson Family."
His account has since been set to private.
Keele University students' union said: "We are deeply saddened to hear the tragic news that Cadet passed away en route to Keele in the early hours of this morning. We would like to offer our sincere condolences to his loved ones at this difficult time."
The up-and-coming artist, from south London, was the cousin of Krept, of duo Krept and Konan.
The Freak Of The Week rapper tweeted: "Absolutely broken."
A second post read: "My life will never be the same again. I love you and will forever miss you. I cant believe it. I am heartbroken. Rest in peace cuz. You finally started getting the recognition you deserved. Im so proud of you. My left lung. Im devastated and broken right now."
Other tributes have also been paid on social media for the star.
Rapper Ghetts wrote: "Just woken up looked at my timeline. Proper genuine brudda cadet. condolences to his close friends and family."
Example tweeted: "Was chatting to you only last week about how excited you were for some festivals this summer. So much positive energy.
"Smiling nonstop when I was with you, first time we met I felt as if I'd known you my whole life. Mad humble guy. RIP Cadet."
DJ Semtex wrote: "Cant believe it... I was on stage with him last week.
"Never seen a man so happy. Everything was working out for him. This was gonna be his year. We were plotting on the best time to do an interview on his next single. RIP Cadet."
Producer Dr Kane tweeted: '"I feel numb my bro you know. I was just speaking to you about our next tune we were gonna drop and shut down this year. I feel sick man !!! RIP cadet."
Cadet stepped into music in late 2015 with a hard-hitting freestyle reaching more than half a million views on social media in just a few months.
This was quickly followed by another heartfelt freestyle, which Complex magazine said was "better than some rappers' whole mixtape".
Cadet went on to have millions of views on YouTube with songs like Letter To Krept, Instagram Girls and Advice.
His management said: "His storytelling capabilities have been described as gripping, with passion, pain and power from beginning to end and his reinvention of grime with new honest concepts mean that you don't necessarily have to be a grime fan to listen and appreciate his lyricism."
He was described as "a rapper who's found a way to vent his frustrations in a way that many people now regularly appreciate".
© Sky News 2019