GENERAL SANTOS (AFP) - Philippine boxer Manny Pacquiao declared he was vindicated over previous drugs allegations from Floyd Mayweather after his American rival was accused of violating anti-doping rules before their mega-fight.

Pacquiao said the "truth finally came out", after it emerged that Mayweather received an injection of vitamins and minerals in the build-up to their fight in Las Vegas in May.

Mayweather and the United States Anti-Doping Agency have both insisted the boxer's actions were legal after a report on the SB Nation sports news website said he had broken World Anti-Doping Agency rules.

"Truth finally came out and I was vindicated," Pacquiao said in a brief statement to reporters in the Philippines late on Thursday.

"(The) Mayweather camp accused me of using PEDs (performance-enhancing drugs). Now look what happened. I hope Floyd Mayweather would learn a good lesson out of (the experience)."

Pacquiao and Mayweather have engaged in a long-running feud which has not abated since the American won their only meeting, for the World Boxing Organisation welterweight title, on points.

Mayweather, who is looking to extend his unblemished 49-0 record against Andre Berto on Saturday, insisted he was a "clean athlete" after the injection came to light.