Spanish figure skater Laura Barquero has become the fourth athlete to fail a doping test at the Beijing Olympics after testing positive for the banned steroid clostebol, the International Testing Agency said on Tuesday. Barquero and her partner Marco Zandron finished 11th in the pairs competition, which finished on Saturday. As well as Barquero's case, there were positive tests in Beijing for Iranian Alpine skier Hossein Saveh Shemshaki and two Ukrainians, cross-country skier Valentyna Kaminska and bobsledder Lidiia Hunko.