Cashtastic, whose real name is Cashief Nichols was detained by the UK Border Agency (UKBA) two weeks ago, the reason why is still unclear.
The 20-year-old, was born in Jamaica but grew up in Peckham in South London.
On Monday he tweeted: “I’ve been detained/given removal directions by the UKBA.”
The rapper first came to Britain 14 years ago to live with his mother.
He attended school from the age of six and has been living in the country ever since.
“They’re saying even though I came to the UK age 6 I have no right to be here,” he tweeted.
Cashtastic was signed to Universal Records last summer and his debut mix-tape Alarm clock was released in February 2014.
His track In the Party was on the 1Xtra playlist and featured on 1Xtra’s Charlie Sloth show earlier this year.
Cashief Nichols Cashtastic performing on 1Xtra’s Charlie Sloth show earlier this year
Jon Barlow is from 3 Beat Records, a company that distributes material on behalf of Universal.
He said it’s the fans who will now miss out: “From a business point of view the decision by UK immigration has cheated him out of a brilliant career and consequently cheated many others of his talents too.”
Some artists have been posting their messages of support to the MC. Rapper Kano said: “This can not be happening to such a good brother like Cashief. A positive brother in the community. He has lived here since the age of 6 and is now a role model, tax paying professional in the music industry. This is wrong.”
A spokesman from the Home Office said they were unable to comment on individual cases but released a statement which read:
“When an individual is found to no longer have the right to remain in the UK, we expect them to leave the country voluntarily, but if they fail to do so we will seek to enforce their removal.”
By Karlene Pinnock
bbc Newsbeat reporter