The World Anti-Doping Agency has dropped another clenbuterol case just weeks ahead of Alberto Contador’s hearing before the Court of Arbitration for Sport.

The Danish cycling federation is reporting Thursday that WADA has withdrawn its appeal against the case involving Danish cyclist Philip Nielsen.

Nielsen tested positive in April 2010 for clenbuterol after racing in Mexico. The Danish sports federation dismissed the case on the argument that the substance may have entered his body via contaminated food in Mexico.

The Danish federation reported that WADA has since decided to drop its appeal against Nielsen, who currently rides on Christina Watches.

The news comes a day after WADA dropped a similar case against Mexican soccer players who tested positive during a Mexican soccer tournament last year.

The two cases could have implications for three-time Tour de France champion Contador, who also claims that traces of clenbuterol entered his system after eating steaks on the second rest day of the 2010 Tour.

In a statement released yesterday, WADA made its strongest declarations in favor of the argument that food contamination is a likely source for triggering clenbuterol positives in some cases.

WADA was careful to limit its comments to cases involving Mexico.

“WADA has subsequently received compelling evidence … that indicates a serious health problem in Mexico with regards to meat contaminated with clenbuterol. This is a public health issue that is now being addressed urgently by the Mexican government,” WADA said in a statement.

It will be interesting to see how things play out in Contador’s case next month.

Contador’s case differs in that he says he consumed meat that he claims was purchased in Spain and brought into France. Clenbuterol has been banned for use in beef since the mid-1990s, though Contador lawyers say there is evidence that European livestock is rife with illegal substances despite stricter laws.