"The rider claims that he incorrectly stated his whereabouts due to private reasons. The committee does not deem this explanation to be credible," the inquiry - led by former Dutch Olympic chief Peter Vogelzang - said in its report.
It added that Rasmussen should not have been permitted to start in the Tour based on the information known to Rabobank at that time.
"The committee concludes that the board of directors of Rabo Cycling Teams in general, and its chairman Theo de Rooij in particular, did not adequately assess the importance of multiple signs concerning Rasmussen's conduct prior to the Tour."
Tour de France
Slipstream ready for Tour challenge
21/03/2008 AT 14:44
Last week, Rasmussen admitted he had lied about his training whereabouts before the Tour but insisted that the Dutch team had always known where he was. He also said he had never doped.
The Rabobank team sacked Rasmussen, who was leading at the time, four days before the Tour's end, saying the 33-year-old cyclist had been in Italy while the Dane said he had been training in Mexico.
Rasmussen returned a 'non-negative' test for the banned substance EPO during this year's Tour, according to the French Anti-Doping Agency in September.
The agency said the result of the analysis of Rasmussen's urine sample could not be declared positive for legal reasons.
The Vogelzang report also said the International Cycling Union failed to act with "insufficient unambiguousness, vigorousness and credibility".
"The UCI must attain a higher level of professionalism with regard to the formulation, enforcement and monitoring of its own doping regulations," it said.
Tour de France
Landis makes final stand
19/03/2008 AT 07:52
Tour de France
Valverde plans late peak of form
09/01/2008 AT 23:27