Jon Jones
Jones was set to meet Cormier in title unification boutGetty

UFC interim light heavyweight champion Jon Jones has been pulled from the UFC 200 main event due to a possible drug test violation.

Just three days before Saturday's (9 July) showpiece card at the T-Mobile Arena in Las Vegas, UFC president Dana White made the shocking announcement that Jones is now under investigation by the US Anti-Doping Authority (USADA).

The 28-year-old tested positive for a banned substance in an out-of-competition sample taken on 16 June by USADA. He was scheduled to headline the event in a title unification bout against Daniel Cormier.

"The UFC organisation was notified tonight that the US Anti-Doping Agency has informed Jon Jones of a potential anti-doping policy violation stemming from an out-of-competition sample collection on June 16," a statement from Jeff Novitzky, the UFC's vice president of athlete health and performance, said. "USADA, the independent administrator of the UFC anti-doping policy, will handle results management and appropriate adjudication of this case.

"It is important to note that under the UFC anti-doping policy, there is a full, fair legal review process that is afforded to all athletes before any sanctions are imposed. However, because Jones was scheduled to compete against Daniel Cormier this coming Saturday, July 9, in Las Vegas, there is insufficient time for a full review before the scheduled bout. Therefore, the bout has been removed from the fight card."

Brock Lesnar vs Mark Hunt will now headline Saturday's card; the third different fight to be placed at the top of the bill after its original headliner Conor McGregor vs Nate Diaz was pulled in April.