Former New Zealand Triathlete Kris Gemmell has been banned from participating in sport for 15 months after failing to comply with normal regulations.
The 37-year-old retired from the sport in 2012 but failed to conform to the requirements of the whereabouts programme.
The whereabouts programme is used by anti-doping organisations worldwide and requires athletes to regularly log details of their whereabouts so that they can be located at any time for "surprise" drug testing.
Drug Free Sport NZ took the case to CAS after it was dismissed by the New Zealand Sports Tribunal in February this year.
Drug Free Sport NZ chief executive Graeme Steel says the CAS decision is important because it clarifies the rules around the whereabouts programme.
"The Court notes that the whereabouts programme is a 'powerful and effective means of deterring and detecting doping in sport."
The ruling confirms that the surprise nature of drug testing that the whereabouts programme allows is important and that Drug Free Sport NZ is right not to give athletes advance notice of testing by telephoning them.
Top level athletes involved in the whereabouts programme need to specify a one-hour timeslot each day in which they will be available for drug testing.
Under the current rules, if they fail to correctly record their whereabouts or miss a test three times in the space of 18-months, it is considered an anti-doping rule violation.
Drug Free Sport NZ argued that Gemmell had missed two tests and filed incorrect information on another occasion within an 18-month period.
The New Zealand Sports Tribunal dismissed the case saying the first missed test should not be counted because "reasonable" steps were not taken to locate Gemmell, namely telephoning him to let him know that an official was at his nominated location to test him.
Steel says CAS did not agree with the Tribunal and he's pleased to have the procedures outlined for both anti-doping organisations and athletes.
Gemmell's 15-month period of ineligibility is backdated from February 12, 2014.