Australian heavyweight boxer Lucas Browne has failed his second drug test of the year, it was revealed on Tuesday.
The Voluntary Anti-Doping Association announced that the 37-year-old's A sample tested positive for ostarine, a substance that causes steroid-like muscle growth without the side effects.
Browne retains the right to request that his B sample be tested.
However, the New South Wales-born boxer has just come off serving a six month ban for testing positive for clenbuterol after beating Ruslan Chagaev in March for the WBA regular heavyweight title, which was later rescinded.
Browne – who is unbeaten after 24 fights – was set to fight American Shannon Briggs for the vacant WBA title before 2017.