The world cycling federation may be unable to prevent riders implicated in a doping scandal from competing in this year's races because there is not enough time to go through a 6,000 page report by Spanish investigators.
UCI president Pat McQuaid said the report into the Operation Puerto scandal is expected soon.
However that may take the rest of the year to sort out which riders should face disciplinary action.
"There is no way we have the eyes to go through these 6,000 pages and determine who is guilty and who is involved in some way or another," McQuaid said.
"There is no way we can be finished before the end of this year. They are the practical issues which make it difficult for us with the best will in the world.
Organisers of the Tour de France and other major races have been pressing to find out which cyclists are implicated in the probe, and McQuaid has asked the Spanish government to help identify the riders involved.
The probe started last May when sports doctor Eufemiano Fuentes, coach Manolo Saiz and six other people were arrested in Madrid on suspicion of providing doping services to cyclists.