The WBO was responding to a Philippines government department's request to review last Sunday's fight after Pacquiao said the decision against him was unfair.
The Philippines Games and Amusements Board's (GAB) said it based their request on protecting boxing's integrity, citing possible miscalls by the referee and judges.
But the WBO reiterated its only hope of revoking the fight judges' decision rests on proving fraud in match officiating.
