Italian athlete Devis Licciardi risks a two year ban after using a fake penis during a doping control.
The 27-year-old was caught with the artificial organ at the Italian championships at Molfetta last Saturday.
After competing in the 10km road race Licciardi was discovered with the device by a controller during a urine test.
Licciardi informed the official that he wanted to be alone to carry out the test only to be told: "No, I have to stay close to you as the rules stipulate," the Gazzetta dello sport reported.
After suspicions were raised and the discovery of the false penis filled with clean urine, the offending object was confiscated for investigation.
The device was hidden in the athletes' underwear.
Licciardi, who was quizzed on Monday by the Italian Olympic anti-doping committee, has declined to comment on the reports.