Rusedski released a statement on Friday revealing he had tested positive for the banned steroid nandrolone at a tournament in Indianapolis last July but will carry on playing until a hearing in Montreal on February 9.

Also Read Rusedski vows to clear his name

The former U.S. Open finalist has protested his innocence and vowed to fight the charges, citing the case of Bohdan Ulihrach, the Czech player who successfully appealed against a two-year ban for testing positive for nandrolone, an anabolic steroid that helps rapid recovery from injury.

Ulihrach won an appeal when it emerged that ATP trainers had been giving players minerals, electrolytes and other supplements, producing an unprecedented number of samples with the same "unique analytical fingerprint".

The ATP immediately stopped distributing the vitamin and nutritional products to trainers in May 2003, two months before Rusedski's positive test.

The organisation released a statement on Saturday saying that while they could not comment on Rusedski's case, there had only been four positive tests for nandrolone in the last eight months and three of those were under the threshold for a positive test.

"Since May 2003 the ATP has strengthened its procedures to guard against the risk of contamination and the presence of nandrolone in tests has largely halted," the statement read.

"The ATP is continuing its efforts to warn players regarding the risk of contamination of health products and the players' responsibilities under the rules of the sport for the presence of any prohibited substances in their bodies."

"The ATP also will enforce the rules of the Tennis Anti-Doping Program, including enforcement of any penalties assessed against a player found by an independent anti-doping tribunal to have committed a doping offence."