A dispute over doping test rules for the planned showdown between Manny Pacquiao and Floyd Mayweather has jeopardised the long-awaited welterweight showdown, promoters claimed. It’s uncertain, however, whether the testing issue is simply an over-hyped negotiating ploy aimed at Pacquiao or truly a deal-breaker that could scuttle a fight with the potential to be the biggest boxing moneymaker of all time.









