Los Angeles - The United States Anti-Doping Agency has denied Floyd Mayweather violated any sporting drug laws on the eve of his fight against Manny Pacquiao.
Floyd Mayweather received an injection of saline and vitamins on the eve of his superfight against Manny Pacquiao.
A strongly worded USADA statement lambasted reports which said Mayweather had breached World Anti-Doping Agency (WADA) rules by having the IV infusion, even though the substances in question were not banned.
The USADA statement said reports on the controversy had contained a "multitude of errors" and were "riddled with significant inaccuracies and misrepresentations."
"We believe it is important to immediately correct the false suggestion that Floyd Mayweather violated the rules by receiving an IV infusion of saline and vitamins," USADA said.
It said Mayweather had applied for and was granted a Therapeutic Use Exemption (TUE) by USADA for the IV infusion, in accordance with regulations set down by the Nevada State Athletic Commission (NSAC).
"Mr Mayweather's use of the IV was not prohibited under the NSAC rules at that time and would not be a violation of the NSAC rules today," the statement said.
It said Mayweather, a voluntary participant in the USADA program, had formally applied for the TUE after the infusion in order to remain in compliance USADA rules.
The agency said although the application was not approved until after the fight, Mayweather "did disclose the infusion to USADA in advance of the IV being administered to him."
"Furthermore, once the TUE was granted, the NSAC and Mr Pacquiao were immediately notified even though the practice is not prohibited under NSAC rules," it added.
A report late Wednesday on the SB Nation website 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 did not immediately respond to requests from AFP for clarification.
The SB Nation report - headlined "Can boxing trust USADA?" - contained broader criticisms of the agency's record in boxing.
USADA defended its record as it condemned reports on the Mayweather case.
"Over the past six years USADA has conducted anti-doping programs for over 45 fights in the sport of professional boxing, and each of those programs has been conducted in accordance with the WADA Code and the International Standards," it said.
"As a result, every athlete who has participated in one of our programs has voluntarily agreed to abide by the rules of the WADA Code and willingly subjected themselves to substantially more stringent testing protocols than they otherwise would have been subject to."