Credit: Facebook Photo: Ricky "Lord Infamous" Dunigan

Three 6 Mafia's founding member Ricky "Lord Infamous" Dunigan has reportedly died at the age of 40. According to HipHopDX, the rapper passed away at his mother's home in Memphis, Tennessee on Friday, December 20.

"He did pass away at his mother's house last night in Memphis," fellow band member DJ Paul's publicist Dove Clark tells HipHopDX. "The cause of death is unknown. We're actually trying to figure out how he died and that is all the information we currently have."

DJ Paul, who is Ricky's half-brother, later told The Hollywood Reporter, "He passed away in his sleep from a heart attack. He said he was tired, he wanted to sleep. He sat down at the kitchen table, put his head in his arms to lay down ... to get some sleep."

Fellow band members reacted to the tragic news on Twitter. "R.I.P. lord infamous," Juicy J tweeted. He added, "Thx you for your prayers, I'm very hurt, can't believe it's true." Rapper Lil Wyte tweeted, "No words can explain how i'm feeling rite now R.I.P. Lord Infamous."

Sources: HipHopDX, The Hollywood Reporter