Matchroom Boxing announced on Tuesday that heavyweight contender Joe Cusumano tested positive for a banned substance in connection to his June fight with Adam Kownacki.

In what was a bruising encounter, Cusumano (22-4, 20 KOs) dropped Kownacki in the first round and then finished him off with a high volume of vicious punches in the eight.

For Kownacki, it was his fourth defeat in a row - and likely the end of the road for his career. 

The official outcome, unless Cusumano can prove his innocence, will become a no-contest.

As far as Cusumano's career, his future is now up in the air - with the New York State Athletic Commission already investigating the matter. 

The win over Kownacki was by far his biggest achievement to date - and helped rebuild his career after being blasted out in a single round only three fights earlier by Daniel Dubois.

"Matchroom can today confirm that Joe Cusumano returned an adverse analytical finding as part of an anti-doping protocol mandated by the New York State Athletic Commission following his bout with Adam Kownacki on 24 June," Matchroom stated on their official social media account.

"We understand a process is underway with the New York State Athletic Commission and Matchroom now defers to the applicable regulatory authorities on the next steps.

"Whilst we are disappointed by the news, this affirms Matchroom's ultimate desire to regularly test active fighters and ensure we continue to promote a clean and fair sport for all athletes. We will not be making any further comment."

News of Cusumano's positive test comes on the back of several high-profile test failures in recent months - including heavyweight contender Dillian Whyte, undisputed super featherweight champion Alycia Baumgardner, and heavyweight contender Robert Helenius.