As five national football players in Mexico are replaced on June 22, 2011 after being suspended for the finding of clenbuterol, a toxic steroid, the players all state the illegal substance came from their ingestion of contaminated meat, with the drug known to still be in widespread use in animal feed despite being banned.

http://ipsnews.net/news.asp?idnews=56171,
http://www.globalissues.org/news/2011/06/21/10180,
http://www.sacbee.com/2011/06/14/3698383/drug-tests-shine-light-on-tainted.html#ixzz1PFKjuTFz