MANILA -- No less than the Nevada State Athletic Commission (NSAC), which is the preeminent state sports body in the US, has cleared Manny Pacquiao of steroids claims made by controversial boxing trainer Floyd Mayweather, Sr.

“All I can tell you is that Pacquiao, every time he's fought here [in Nevada, has] been tested, as well as his opponents,” said NSAC executive director Keith Kaiser.

“He passed every drug test we did to him, every steroid test we did to him,” he added to counter allegations made by Mayweather Sr. that Pacquiao was into performance enhancement drugs.

Mayweather Sr. is the father of former world champion Floyd Jr., whom Pacquiao succeeded as the world’s top pound-for-pound fighter.

According to Wikipedia, the NSAC is regarded as the preeminent state athletic commission in the US because of Nevada's role as a center for combat sports. The commission regulates all boxing matches in the state of Nevada and has the final authority on licensing matters, having the ability to approve, deny, revoke, or suspend all licenses for boxing bouts.

Kaiser stressed that the NSAC conducts stringent drug tests on boxers before allowing them to fight within the jurisdiction of Nevada.

“[On] title fights [we have] tests for steroids and drug abuse. [We look out for] marijuana, cocaine,” said Kaiser. “We collect urine [for tests] before and after the fight.”

Still at it

Mayweather Sr., meanwhile, insisted that Pacquiao used “some sort of supplements” which is why he was able to maintain his punching power despite climbing several weight divisions.

“He's never been that kind of puncher and all of a sudden he's a gigantic puncher,” said Mayweather Sr.

Pacquiao, who first became a world champion as a flyweight, climbed the welterweight division and defeated Oscar de la Hoya in eight rounds. He also stopped Ricky Hatton, a natural junior welterweight, in two rounds.

“I felt that he was on steroids or some type of supplements or some type of enhancement drugs… believe me when I tell you, he's going to get caught,” said the controversial boxing trainer.

‘Liable for slander’

Pacquiao’s coach, Freddie roach, said a slander case s already in the works against Mayweather Sr.

"I am going to talk to my lawyer, there could be a slander case here, and we will sue him,” Roach told Brad Cooney of 8CountNews and Examiner.com.

The Hall-of-Fame coach said Pacquiao agrees with him that Floyd Jr.’s father should be held liable for his comments.

“I talked to Manny, and I talked to an attorney, and we are all on board here. This is all over the place now that Manny is on steroids, it's defaming his name," said Roach.

The Filipino boxer earlier said that he has also sought legal advice on Mayweather Sr.’s comments.

“Kinonsulta ko ang abugado ko para suriin [ang sinabi ni Mayweather Sr.] at kung lumabag siya ay kelangan niyang panagutan,” he said.

Pacquiao said he never considered using steroids and has consistently passed medical test for his fights in the Philippines and abroad.

“Lahat ng laban ko, lahat ng medical ko wala namang problema, pero itong si Floyd Mayweather [Sr.] parang may diperensya doon sa mga sinasabi niya,” said the boxer. With a report by Dyan Castillejo, ABS-CBN News