It was less than a month before the 2012 election when a spokesman for Black Men Vote, a political group backed by hip-hop musicians including Common and Pras Michel, publicly announced: “I want a $500,000 donor.” Three days later, his wish was all but granted. That’s when a cool $400,000 landed in the bank account of Black Men Vote, a super PAC whose goal was mobilizing young Black men to support President Barack Obama’s re-election. The source of the money? An obscure limited liability company identified as SPM Holdings LLC with an address in Palm Beach Gardens, Florida.

By Election Day, SPM Holdings would double down and make an additional six-figure contribution, bringing its total financial support of Black Men Vote to $875,000. It was one of the largest donations to a super PAC ever by a limited liability company, according to a Center for Public Integrity review of federal campaign finance records. Moreover, the LLC money represented two-thirds of the $1.3 million Black Men Vote raised in 2012. That’s a larger portion of money than any other top-tier super PAC has received from limited liability companies—business entities that can be used to shield the identities of people making large political contributions.

Federal records would eventually show that Pras, a Grammy-winning rapper and founding member of the Fugees, provided $250,000 in seed money for the super PAC’s efforts and another $100,000 before Election Day. “The best way we can make a change is empowering one another,” Pras told the Center for Public Integrity in a recent interview. “I put my money where my mouth was.” But the donor (or donors) behind SPM Holdings would remain—until now—a mystery.