Astana rider llya Davidenok has failed a doping test, resulting in his team having their WorldTour elite status reviewed by the International Cycling Union.
An adverse finding for anabolic steroids was the reason for the positive test of Davidenok, whose failed test came at the junior Tour de France in August.
Astana's participation in the major Tours for 2015 could now be in doubt, with Davidenok's test coming on the back of Maxim and Valentin Iglinskiy testing positive for EPO earlier this year.
The team are headed by Vincenzo Nibali, who won the Tour de France in July.
