The Operación Puerto doping case (meaning Operation Mountain pass) is a doping investigation in Spain. It started in May of 2006.
Dr. Eufemiano Fuentes is accused of giving banned doping drugs to 200 professional athletes.
Fuentes doped a lot of well known tennis and football stars but most attention was on the fairly small number of professional road cyclists that were named in the investigation.
By May 2007, fifteen have been proved not guilty, but three have admitted doping or have had very much evidence of blood doping placed before them.