Nandrolone the old favourite

The most common performance-enhancing drug used by footballers in recent years has been nandrolone. The first positive test for the substance in England was in October 2002, by an unnamed player outside the Premiership.

A spate of nandrolone positives the previous year included the Dutchman Jaap Stam, soon after his move from Manchester United to Lazio, and his compatriots Edgar Davids, who served a four-month ban at Juventus, and Frank De Boer (a two-month ban at Barcelona). Fernando Couto (Lazio and Portugal) and Pep Guardiola (Spain and Brescia) also served nandrolone bans in Italy, where 10 tested positive in one season.

In 1999, a Turin magistrate, Raffaele Guariniello, began an investigation into the history of doping in Italian football, identifying 70 "suspicious" deaths among former footballers who had played professionally in Italy between 1960 and 1996. He concluded that consumption of "doping-style substances", perhaps without the players' knowledge, was a possible explanation for statistically high occurrences of various fatal illnesses.

Guariniello's inquiry began when police uncovered 281 types of drugs in a room in a stadium where Juventus trained.