Terrell Owens says Tom Brady is a cheater. Ditto for Bill Belichick and the rest of the Patriots ... and it's all on video.
T.O. was playing some pickup basketball with Sam Cassell -- and, while joking around after the game, he playfully accused Sam of cheating. That's when the anti-Pats trash talk began.
"You sound like the Patriots. You know what I mean?" T.O. says ... "I don't care about the Patriots. Belichick, Brady -- they cheaters. They cheated. They cheated."
So, why the attack?
Well, the Pats beat T.O.'s Eagles in Owens' only Super Bowl appearance back in 2005 -- and just a few years later ... they were busted for Spygate.
Owens still seems to have a soft spot for Brady, though ... 'cause when Sam says he'd be a Pro Bowl player TODAY if he were playin' with the G.O.A.T. -- Owens doesn't disagree.