ANTHONY JOSHUA and Oleksandr Usyk both had their last drug tests after their fight last month.
The two heavyweights met in 12 rounds in front of 63,000 sold-out fans at the Tottenham Hotspur Stadium.
The Briton has lost three of his world titles after being shocked by a unanimous loss to the Ukrainian.
And the Voluntary Anti-Doping Agency (VADA) confirmed that the samples of the two fighters had returned healthy.
Joshua and his opponents typically sign up for a testing program ten to 12 weeks before a fight.
This saw a previous predicted opponent, Jarrell ‘Big Baby’ Miller, miss a shot against the former Olympic gold medalist.
Joshua then fought Andy Ruiz Jr, who shocked and knocked him out at Maddison Square Garden.
The Watford slugger then avenged the loss, leading the Mexican to 12 rounds in the Saudi desert.
These two fights, as well as his next against Kubrat Pulev at the o2 Arena were all clean encounters.
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Meanwhile, Joshua has revealed in the past how drug testers follow fighters everywhere when they show up.
He said in the past: “The testers follow you everywhere when they arrive, even when you (gestures while urinating).
“They jump in the car with me all the way to Nando’s, I can’t drive on my own. It’s difficult, managing his comings and goings, it’s quite boring.”