The artist Yassin Bey formerly known as MosDef, has been barred from re-entering the United States for legal and immigration reasons.

Bey was previously scheduled to perform at the festival’s May 15 show at the Wilbur Theatre.

The Together Boston music festival posted on its website, “We regret to inform you that due to immigration / legal issues Yasiin Bey is unable to enter back into the United States and his upcoming U.S. tour has been cancelled.”

Bey has been living in South Africa for the past year after a visit last May inspired him to leave Brooklyn and make the transatlantic trek.

Rumors are swirling about that Bey gave up his U.S. citizenship in making the move, while others speculate his outspoken stances against American hostage policies may be at the root.

An outspoken critic many of US policies, Bey made national headlines last July after volunteering to undergo a force-feeding treatment that is commonly used on detainees at the Guantanamo Bay prison.