Jarrell Miller, who was denied a license by New York boxing officials over a failed test on Wednesday, has now failed two more tests for other banned substances.
As BoxingScene.com reported earlier today, a second failed drug test has come to light with Miller testing positive for human growth hormone (HGH). That test was taken on March 31.
Miller's initial failed test was reported earlier this week, with the banned substance GW1516 coming up from a test taken on March 20. GW1516 is used to assist in fat loss or as an endurance booster.
Miller's planned June 1 fight against world heavyweight champ Anthony Joshua had already been scuppered by the first failed drug test which came down on Tuesday.
Miller, who is undefeated in his 24 professional fights, was due to take on the Briton at Madison Square Garden for the WBA, IBF, IBO and WBO titles.
According to ESPN, Miller's third test, also taken on March 31, came up positive for EPO - which is increases the oxygen-carrying capacity of blood, and he was once again positive for GW1516.
Miller previously served a nine-month ban from the California State Athletic Commission after testing positive for methylhexaneamine when kickboxing in 2014.
Following the news of the first failed test, Miller took to social media and denied that he ever took any performance enhancers to prepare for Joshua - but he's gone quiet since the news of his two additional failures.
Promoter Eddie Hearn, who handles Joshua, said he was scrambling to find an alternative opponent for the British star's highly anticipated United States debut.
Hearn is expected to announce Joshua's next opponent as early as this coming Tuesday. At the moment, United States Olympian Michael Hunter appears to be the frontrunner. Hunter recently signed a promotional pact with Hearn.