Jontay Porter has just been banned from the NBA for LIFE ... after league officials say the Toronto Raptors player not only bet on NBA contests -- but he tried to help gamblers win cash by limiting his minutes during a game too.
Adam Silver just announced the historic punishment on Wednesday ... explaining league investigators discovered that in March, Porter took part in a gambling scheme that ultimately called into question the integrity of the NBA's competition.
They claim the 24-year-old told confidential information about his health to at least one known bettor.