Boxing: Truth out about Mayweather, says Pacquiao

Pacquiao said the "truth finally came out" after it emerged 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 (USADA) 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 (WADA) 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 Organization 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.

"I follow and have always followed the rules of Nevada and USADA, the gold standard of drug testing," he said in a statement.

"I am very proud to be a clean athlete and will continue to champion the cause," Mayweather added.

Random test

Mayweather's fight with eight-division world champion Pacquiao was delayed for years partly because of his insistence that the Filipino comply with a strict drug-testing regime.

Mayweather later accused Pacquiao of using performance-enhancing drugs. The Filipino sued and the two settled out of court.

The aftermath of their fight has also been rocky, after Pacquiao revealed he was carrying a shoulder injury and was branded a "sore loser" by Mayweather.

The SB Nation report said Mayweather's infusion had come to light after USADA agents visited the boxer at his Las Vegas home on Friday May 1, the day before the Pacquiao fight, to conduct a random unannounced test.

The report said the IV consisted of two separate mixes of saline and vitamins which had been administered to address dehydration concerns.

It added that while the substances in question were not prohibited under WADA rules, administering them intravenously was a breach of WADA regulations.

WADA guidelines say IV infusions are prohibited because they can be used to mask the use of performance enhancing drugs, increase plasma volume levels and distort the values of an athlete's biological passport.

However a USADA source later told AFP that because Mayweather obtained a TUE (therapeutic use exemption), no offence had been committed under WADA rules.