Former Team Sky rider and three-time world time trial champion Michael Rogers has been provisionally suspended and could be banned after failing a drugs test.
Rogers, 33, tested positive for banned substance clenbuterol at the Japan Cup in October and is suspended by the International Cycling Union (UCI) while his national federation investigates the case.
The Australian is the second rider to be investigating following doping allegations in recent weeks with Team Sky's Jonathan Tiernan-Locke facing punishment following analysis of his biological passport.
Rogers' team released a statement claiming his positive result was due to a contaminated food source: "Michael Rogers immediately informed Saxo-Tinkoff's management about the notification from the UCI," the statement read.
"The Australian explained to the team management that he never ingested the substance knowingly nor deliberately and fears that the adverse analytical finding origins from a contaminated food source."
Rogers left Team Sky, where he rode in support of Sir Bradley Wiggins in the Britain's 2012 Tour victory, and joined Saxo-Tinkoff last season after being named as part of evidence in Lance Armstrong's case.
In a similar case Spaniard Alberto Contador was banned from cycling for two years as after testing positive for the fat burning, muscle building drug clenbuterol at the 2010 Tour de France.
Rogers will wait to hear if he faces the same fate.