The International Cycling Union says Alberto Contador's Saxo Bank-Sungard team could be thrown out of cycling's World Tour.
The Spaniard was given a two-year doping ban by the Court of Arbitration for Sport earlier this week.
The Danish team is run by Bjarne Riis, who won the 1996 Tour de France but later admitted to doping during the race.
Contador was stripped of one of his three Tour titles and banned for two years by CAS for failing a dope test during the 2010 race.
The 2007, 2009 and 2010 Tour winner, widely regarded as the greatest cyclist of his generation, tested positive for the banned anabolic agent clenbuterol.
The 29-year-old has also had all his other victories last season nullified, including his Giro d'Italia success, and will not be able to take part in the 2012 Tour or London Olympics.