The suits, which will include Oscar de la Hoya's Golden Boy Promotions, will follow an impasse during negotiations for a March 13 Pacquiao-Mayweather title fight.
Mayweather claimed Pacquiao would not comply with Olympic style drug testing as outlined and mandated by the United States Anti Doping Agency.
"Enough is enough," Pacquiao said Friday on his Web site. "These people … think it is a joke and have a right to accuse someone wrongly of using steroids or other performance-enhancing drugs. I think they have gone overboard. I maintain and assure everyone that I have not used any form or kind of steroids."
Pacquiao added he would enlist the help of Top Rank's Bob Arum, the original promoter of the multimillion-dollar bout.
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