London’s Okolie (23-1, 17 KOs) was slated to box Yoka (15-3, 12 KOs) in a 12-round contest, headlining Queensberry’s latest foray into Europe after success with Agit Kabayel in Germany on January 10. DAZN was scheduled to stream the event globally.

The Voluntary Anti-Doping Association administered PED testing for the Yoka-Okolie bout and informed Queensberry of the adverse finding.

Okolie responded to the initial news of his adverse finding on Instagram with an image lying down and his left arm strapped with kinesiology tape isolated, accompanied by a caption which reads:

“Before anyone starts imagining the worst, following my bicep[s] injury last year, I sustained an elbow injury on the same arm during this camp. I had a treatment on it and now we are here. I truly hope sense prevails.

“I will of course be fully cooperating with all relevant authorities and I’m confident any investigation will clear my name. I won’t be making any further comment at this time. Thank you for all your support and see you soon.”

Okolie and Yoka, a 2016 Olympic gold medalist from Paris, returned with knockout victories in Nigeria against overmatched opposition on December 21 before agreeing terms to fight, aware the divisional landscape necessitated a marquee win as world titles will likely fragment again.

Okolie is the WBC’s No. 1 contender for Ring, IBF, WBA and WBC champion Oleksandr Usyk, who will defend his crowns against Rico Verhoeven in the main event of a Ring-sponsored card May 23 at the Pyramids of Giza, just outside of Cairo, Egypt.

Yoka is not ranked in the top 15 by the WBC. Kabayel (27-0, 19 KOs) holds the WBC interim title.

A WBC super welterweight title eliminator between Queensberry’s new acquisition, French contender Bakary Samake (19-0, 11 KOs), and Albania’s Ermal Hadribeaj (22-0-1, 8 KOs) was the scheduled co-feature on the Yoka-Okolie card. Irish heavyweight prospect Adam Olaniyan was announced as a late-notice addition to the bill last weekend.

EDITOR’S NOTE: This is an updated version of a story posted earlier Tuesday.