The World Anti-Doping Agency has warned cycling's governing body it may carry out its own investigation into allegations against Lance Armstrong.
Armstrong claims he is the target of a media "witch hunt"
The International Cycling Federation (UCI) has set up an independent inquiry to investigate claims Armstrong doped during the 1999 Tour de France.
"If it is not a thorough investigation we will decide accordingly what to do," Wada chairman Dick Pound said.
"(That) may include our own investigation."
Last August, French newspaper L'Equipe published allegations that samples Armstrong had given during the 1999 Tour de France contained traces of the banned blood-boosting substance EPO.
Armstrong, who has won a record seven Tours de France, has always vehemently denied the allegations.
The American has described them as "persecution" and part of a "witch-hunt", and also criticised the manner in which L'Equipe obtained the samples from a French laboratory.
Last October, the UCI set up an independent inquiry, headed by Dutch lawyer Emile Urijman, to look into the allegations.
"We will wait and see what the outcome of that investigation is," Pound told BBC Sport.
"The UCI says it is fully investigating the matter and, because it's the responsible international federation, our view at the World Anti-Doping Agency is to let them do it.
"If it is not in fact a thorough investigation of everything that happened - including how the information got into the hands of L'Equipe - then we will decide accordingly what to do, which may include our own investigation."
Pound has frequently been at odds with both the UCI and Armstrong in the past.
When the allegations were first made, Pound said: "It's a pretty serious story if it is true."
A UCI spokesman criticised him for making "public statements about the likely guilt of an athlete on the basis of a newspaper article and without all the facts being known".
The UCI also said, "a Wada inquiry would be based on areas out of its competence".
In 2004, Armstrong wrote an open letter to European newspapers saying that Pound should not be in charge of Wada.