LUIS NERY, who emphatically dethroned long-reigning WBC bantamweight champion Shinsuke Yamanaka earlier this month, has tested positive for a banned substance.

Yesterday the WBC confirmed that, as part of its Clean Boxing Program, Nery failed an out of competition test prior to his fight with Yamanaka in Japan on August 15.

The Mexican tested positive for Zilpaterol, which is very similar to Clenbuterol, and is typically used to increase the size and bulk of cattle.

“The WBC Clean Boxing Program will begin the process according to its protocol  and will provide additional information during the process,” a WBC statement read.

The tests were carried out by the Voluntary Anti-Doping Agency (VADA), who administer all tests under the WBC Clean Boxing Program.

These findings mean Nery’s fourth-round stoppage win could be changed to a no contest and the title be returned to Yamanaka, or it could become vacant.

Nery, who was fighting out of Mexico for the first time when he challenged Yamanaka, was mandatory challenger when he wore the 34-year-old down and battered him into submission in the fourth.

Yamanaka, who won the title back in 2011 and was making the 13th defence of it, suffered his first professional loss at the hands of Nery – but could see that reversed.