A UFC fighter has failed a drug test, but will not be suspended.

Ning Guangyou of China tested positive for clenbuterol from an out-of-competition sample taken May 19, but USADA found he ingested the substance without fault or negligence, it was announced Tuesday in a release.

Countries like Mexico and China have a high risk for meats contaminated with the substance. WADA issued a warning about the issue in 2011.

"Consistent with numerous prior reported cases globally, the issue of illicit administration of clenbuterol to animals destined for food production can result in, under specific conditions, a positive sample from an athlete," the USADA release stated.

Guangyou, 34, tested positive for only trace amounts of clenbuterol. USADA said it reviewed the evidence of the case — Guangyou's whereabouts, dietary habits and the lab reports showing "very low parts per billion concentrations" of the substance — and determined that it very likely came from tainted meat. Guangyou will not face a suspension.

"While the risk of consuming clenbuterol-tainted meat and testing positive for an athlete is extremely small, consistent with past athlete advisories, USADA reminds athletes to use the utmost care if eating meat in known high risk countries, including Mexico and China," the USADA release stated. "In line with WADA recommendations, USADA will continue to assess the presence of clenbuterol in an athlete's sample on a case by case basis, taking into account all the evidence supporting the likelihood of such contamination."

Guangyou's bout with Marlon Vera has been moved from UFC 202 to one week later at UFC on FOX 21 on Aug. 27 in Vancouver, the UFC announced Tuesday.

The UFC statement reads:

In late July, UFC was made aware of USADA's investigation into the source of the prohibited substance clenbuterol in an out of competition sample collected from Ning Guangyou. Given it was initially unclear as to the timing of the resolution of the investigation, UFC made the decision to move Guangyou's scheduled bout against Marlon Vera on August 20, 2016 at UFC 202 to UFC Fight Night: Maia vs. Condit in Vancouver, BC on August 27, 2016.

A similar issue with clenbuterol occurred earlier this year before a boxing match between Francisco Vargas and Orlando Salido. Vargas, a Mexico native, popped for clenbuterol two months before the fight, but the California State Athletic Commission (CSAC) and the Voluntary Anti-Doping Agency (VADA) allowed the fight to go on after Vargas had passed every other out-of-competition test leading up to the June 4 date. The situation was discussed at length last week at the Association of Boxing Commissions and Combative Sports (ABC) annual conference last week in Las Vegas.

Guangyou (5-3-1) has not fought since a split decision loss to Marco Beltran last November. He won his first two fights in the UFC before that, including the TUF China championship over Jianping Yang in 2014. He has never fought outside of Asia.

Clenbuterol is clinically used by asthma patients, though it's stimulant and slight anabolic qualities have put it on WADA's banned list as a performance-enhancing drug.