The career of heavyweight contender Lucas ‘Big Daddy’ Browne of Australia is under serious threat after he reportedly failed a second drug test this year.

ESPN reports 37-year-old Browne, who was due to fight for the vacant WBA ‘regular world title against US veteran Shannon Briggs, tested positive to a banned substance in a Voluntary Anti-Doping Association (VADA)-conducted drug test in Australia.

It follows Browne testing positive for clenbuterol after beating Ruslan Chagaev to win the WBA regular belt in Chechnya in March. Browne was stripped of the title and suspended by the WBA but appealed and was allowed to fight for the title again after officials accepted he did not knowingly ingest the substance.

ESPN’s Dan Rafael said on Tuesday Browne has tested positive for a second time as part of the WBC’s Clean Boxing Program, which the boxer voluntarily enrolled in.

“We have been notified by VADA about Browne’s adverse finding as he was tested under the CBP,” WBC president Mauricio Sulaiman told ESPN.

“He has been notified and the process is being attended as per the protocol.”

Browne is yet to comment on the information.