The international doping watchdog said Italian athletes accounted for 147 anti-doping rule violations in 2016, the most recent year for which full figures are available.
French athletes accounted for the next highest number on the list with 86 cases, while the United States was third with 76. Australia were fourth with 75 and Belgium fifth with 73. Russia and India were next with 69 cases each.
Athletics had more cases than any other individual sport with 205, ahead of bodybuilding with 183.
Cycling was third with 165 cases while the drug-tainted sport of weightlifting was fourth with 116. Football moved up to fifth in the rankings with 79 cases, though the total number of cases was smaller than 2015, when they reported 108 cases.
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In total, WADA dealt with 1,595 doping rule violations across 112 sports in 2016, down from 1,929 cases in 2015.
A total of 1,326 rule violations arose from positive drug tests, while the remainder were derived from investigations and evidence-based intelligence, increasingly seen as a key weapon in the war on dope cheats.
“We are continuing to see the impact of intelligence-based testing, an area of increasing focus for the agency as we strengthen our investigations and intelligence-gathering capacity,” WADA President Craig Reedie said in a statement.
“While in- and out-of-competition testing remains critical to detecting doping, recent events have shown that investigative work is becoming ever more important as we look to protect clean athletes' rights worldwide,” he added.