By Jonathan Overend
BBC tennis reporter
Jars of supplements were often left unattended at tournaments, according to the first investigation into the nandrolone scandal that has rocked tennis and left Britain's Greg Rusedski facing a possible drugs ban.
The Young Report, an independent investigation published in the summer, made a number of key observations.
But it failed to draw any definite conclusions as to how nandrolone appeared in the system of so many players.
The notable finding is that before the end of May 2003, "products were often dispensed by ATP trainers from open containers which were left unattended in training rooms at tournaments".
This was without the authority of the ATP and despite repeated warnings to players not to take supplements because of the risk of contamination.
Although key aspects of the Young Report are sure to feature in Rusedski's defence, it is unclear whether the "unattended container" evidence will assist him.
He tested positive on 23 July, 2003, almost two months after distribution of ATP supplements was halted.
Although nandrolone can stay in the system, the International Tennis Federation has claimed such a small sample would disappear in "days rather than weeks".
The Young report is written by Richard Young, an expert on anti-doping who helped lead the team which drafted the World Anti-Doping Agency code.
His investigation helped exonerate Bohdan Ulihrach and six other unnamed players because the ATP were legally unable to enforce their anti-doping rules.
"The ATP has not been able to definitively establish that contamination of the electrolyte product or other supplements distributed by its trainers was not the source of these positive and near positive tests," said the report.
Also, despite reports suggesting 47 players had failed tests, Rusedski remains the only new positive test in six months.
The vast majority of the 47 recorded raised levels of nandrolone but inside the legal limit.