Jay-Z is helping to pay 21 Savage's legal bill.
The hip hop mogul reached out to secure support after his friend was arrested by ICE (Immigration and Customs Enforcement) at the weekend, who said they had "arrested unlawfully present United Kingdom national Sha Yaa Bin Abraham-Joseph AKA '21 Savage' during a targeted operation with federal and local law enforcement partners" because he is "unlawfully present in the U.S. and also a convicted felon."
Attorney Alex Spiro confirmed to E! News that he was helping in the case after being hired by Jay and Roc Nation.
The '99 Problems' hitmaker - who has daughter Blue Ivy, seven, and 19-month-old twins Rumi and Sir with wife Beyonce - has also branded the ongoing detainment of the 26-year-old rapper an "absolute travesty" and called for him to be released and reunited with his three kids.
He said in a statement: "The arrest and detention of 21 Savage is an absolute travesty, his U visa petition has been pending for four years.
"In addition to being a successful recording artist, 21 deserves to be reunited with his children immediately #Free21Savage."
Alex has vowed not to stop working on the case until the 'Rockstar' hitmaker is released, insisting his client is a "wonderful person" who deserves his freedom.
He said: "We are not going to stop until he is released, bonded out or in front of a judge...What we have here is someone who overstayed their Visa with an application pending for four years - not a convicted criminal that needs to be detained and removed but, by all accounts a wonderful person, father, and entertainer who has a marijuana offense which was vacated and sealed."
The rapper's legal team have previously clarified that their client was born in London and moved to America when he was seven years old.
They explained how Savage was born in the UK and arrived legally in the US under an H-4 visa, where he stayed until 2005, when he left for around a month to visit his country of birth, before returning, again under a valid H-4 visa, in July 2005.
However, that expired the following year "through no fault" of the rapper.
The statement continued: "Mr. Abraham-Joseph has been continuously physically present in the United States for almost 20 years, except for a brief visit abroad. Unfortunately, in 2006 Mr. Abraham-Joseph's legal status expired through no fault of his own.
"Mr. Abraham-Joseph, like almost two million of his immigrant child peers, was left without immigration status as a young child with no way to fix his immigration status. These 'Dreamers' come from all walks of life and every ethnicity.
"Mr. Abraham-Joseph has no criminal convictions or charges under state or federal law and is free to seek relief from removal in immigration court. ICE provided incorrect information to the press when it claimed he had a criminal conviction."