Manny Pacquiao has called for the WBO to review the "unfair decision and officiating" that led to his shock defeat to Jeff Horn.

Pacquiao lost the welterweight title to Horn by unanimous points decision in Brisbane on Sunday, the seventh loss of the veteran fighter's career, despite appearing to have the better of the fight and coming close to stopping the Australian in round nine.

The Philippines Games and Amusements Board wrote to the WBO requesting a review on Monday and suggested the referee and judges could merit sanctions.

Pacquiao has echoed those calls by outlining his concerns for the future of boxing in the wake of the bout.

"I love boxing and I don't want to see it dying because of unfair decision and officiating," Pacquiao said in a statement.

"I had already accepted the decision but as a leader and, at the same time, fighter I have the moral obligation to uphold sportsmanship, truth and fairness in the eyes of the public.

"WBO should take appropriate action on the letter sent by the Games and Amusement Board so as not to erode the people's interest in boxing."

Pacquiao previously claimed referee Mark Nelson favoured Horn, commenting: "There is no problem with the style of Jeff Horn if he plays dirty, because there is a referee.

"The problem here is that the referee, I don't know if he did it deliberately or he just did not have experience, he just allowed it and did not even give any warning for how many times. It's as if the referee wanted to help my opponent."