Christopher "Big Black" Boykin, one half of MTV's Rob & Big, has died, TMZ reports. Boykin was 45.

According to TMZ, Boykin died sometime Tuesday morning. While there is no official cause of death, TMZ sources suggest that he fell victim to a heart attack.

Boykin served as Rob Dyrdek's bodyguard and best friend on the popular MTV reality show, which ran from 2006 to 2008. He also later appeared on Dyrdek's subsequent series Fantasy Factory, as well as Ridiculousness, MTV Guy Code and MTV Snack Off.

He is survived by his young daughter.