MANILA (AFP) - Philippine boxing hero Manny Pacquiao expressed renewed anger on Wednesday over allegations that his American rival Floyd Mayweather had violated anti-doping rules in the build-up to their mega-fight in May.

Mayweather had accused him of illegal doping before their fight, only to have similar accusations surface against the American.

"We have rules in boxing. The penalty (for Mayweather) will also be based there. He must face that if allegations that came out against him are true," Pacquiao said when the press raised the subject as he made a public appearance in Manila.

The Filipino, who won world championships in eight weight divisions, decried the way he was treated by boxing officials seeking to prevent doping before the fight in Las Vegas in May which Mayweather won by unanimous decision.

"I have more than 20 years of boxing experience but that was my first time that I was treated that way. Even my own mineral water, my Gatorade were not allowed inside my dressing room. How come?" he said.

After the fight, it emerged that Mayweather had received an infusion of vitamins and minerals the day before the match but both Mayweather and the United States Anti-Doping Agency (Usada) have insisted that this was legal.

But Pacquiao has questioned why Usada only informed the Nevada State Athletic Commission about the infusion three weeks after the bout, by which time Mayweather had already received a Usada exemption.

He had previously called for unspecified sanctions and a rematch with Mayweather.