The rapper believes the 'Fast & Furious 6' star, who died in a car crash in November, and his co-star Vin Diesel only won out of "sympathy" on Sunday night (13.04.14), and insists he and his 'Ride Along' co-star Kevin Hart were "robbed."
The 44-year-old actor told USA Today newspaper: "We was robbed. Shame on you, MTV."
He added: "We had the best chemistry of everybody nominated, for us not to win was crazy. We were the best onscreen duo, period."
Paul was also honoured during a special tribute led by his co-star Jordana Brewster at the star-studded event.
But Ice Cube claims he wasn't suggesting the late actor, 40, wasn't talented enough to receive the accolade, saying: "They should have gave it to him before he passed away."
The actor also left the ceremony, hosted by Conan O'Brien at the Kodak Theatre in Los Angeles, mid-show because he wasn't enjoying himself.
He said: "I just wasn't into it. I have been going in and out of these things for 25 years. If you ain't into it, why torture yourself? As soon as you get bored, get up and leave."
Shortly before the awards, he wrote on Twitter: "On my way to the MTV movie awards. If me and Kevin Hart don't win. The fix is in."