Newcastle NRL star Jarrod Mullen will challenge a four-year ban after testing positive to a banned anabolic steroid.
Mullen was stood down in January after he allegedly tested positive last November to Drostanolone.
He was issued with a Notice of Alleged Anti-Doping Rule Violations last week after his B-Sample returned positive, however he has elected to try to challenge the suspension.
"He has opted to take the matter to the anti-doping tribunal," a NRL spokesman said.
No date has been set yet for the hearing, but it is likely to take place in the next few weeks before Ian Callinan QC.
Mullen, 29, with 211 matches for the Knights and one State of Origin for NSW since his debut in 2005, has struggled in recent years with hamstring injuries.
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