(REUTERS) - Floyd Mayweather and Manny Pacquiao have agreed to take part in a US Anti-Doping Agency (Usada) Olympic-style testing programme ahead of their May 2 mega-bout in Las Vegas.

Drug testing had long been a major stumbling block in bringing together the biggest drawcards of their generation but Usada confirmed on Friday that both fighters have consented to rules established under the World Anti-Doping Code and the World Anti-Doping Agency (Wada) banned-substance list.

"It's a strong statement of the importance of clean and safe competition to have these two fighters voluntarily agree to have a Wada-level, anti-doping programme implemented for this fight," said Usada CEO Travis Tygart.

The welterweight showdown between the undefeated Mayweather (47-0) and Pacquiao (57-5-2) is projected to be the most lucrative ever in boxing but was delayed for years over the American's demands that his Philippines' opponent submit to drug testing.

The two have enrolled in Usada's registered testing pool by providing their whereabouts so they can be located for out-of-competition testing prior to the fight.

Usada will also perform in-competition testing after the fight.

Both fighters agreed to blood and urine testing.