The Dutch sports umbrella organization ­NOC*NSF has begun testing the urine of athletes for evidence of doping – not by the athletes, but by the livestock farmers that produce their meat, the Volkskrant said on Tuesday.

Athletes who consume meat in Asia and South America may be ingesting unknown contaminants, the sports body says. Now a lab in the Netherlands has been testing the urine of Dutch athletes returning from competition abroad.

On Monday, athletes – including medalists Kjeld Nuis, Jorien ter Mors and Kai Verbij – returning from the world sprint speed skating championships in Seoul were asked to provide a urine sample shortly before arrival at Schiphol.

As sports organizations often have no definitive answer exactly what kind of contaminants are found in meat around the world, these urine samples allow regulatory bodies to collect data and draw up a proper list, Dutch Olympic team doctor Cees-Rein van den Hoogenband told the Volkskrant.

False Positives

Clenbuterol is of particular interest to Van den Hoogenband. Administered to animals in some countries as an anabolic agent to promote muscle growth, Clenbuterol is often used by athletes to accelerate weight loss while preserving muscle mass.

Thus, athletes who have tested positive for this banned substance may have ingested it unwillingly through contaminated meat.

The World Anti-Doping Agency’s methods for distinguishing intentional from unintentional Clenbuterol use are still being developed, and several studies in the Netherlands have been funded by the agency.