Italy striker Giuseppe Rossi proclaimed his innocence and evoked the possibility of "involuntary food contamination" after testing positive for the banned substance dorzolamide, media reports said Tuesday.

Rossi, who has played 30 times for the Azzurri in a career blighted by knee injuries, tested positive following an Italian league match between his team at the time, Genoa, and Benevento on May 12. Dorzolamide is commonly found in eye drops. Its use is permitted if the athlete obtains a therapeutic use exemption, although if not applied to the eyes, it could be used as a diuretic.