The CAS panel said in a statement that the conclusion had been reached "with some considerable regret". Shoaib and Asif tested positive for the banned steroid nandrolone in internal tests conducted by the Pakistan Cricket Board (PCB) last year, and were banned for two years and one year respectively in November 2006.
However, a month later, both were controversially reinstated by a Pakistani appellate committee, prompting WADA to appeal to CAS in Lausanne. Dick Pound, the chairman of WADA, had told the BBC last December that the ICC - the game's governing body - was "a signatory to the anti-doping code" and that Pakistan, as a full member of the ICC, was bound by its rules.
However CAS, which set up a special panel to examine the issue, found that the PCB does not provide a right of appeal to the international sports court. Furthermore, it added, the ICC's code did not contain any rules that obliged the Pakistan board to allow appeals to CAS.
Shoaib and Asif were both removed from their country's squad for the World Cup in March and April, although the PCB insisted they had missed the event because of injuries. That explanation, however, was countered by Malcolm Speed, the ICC's chief executive, who said at the beginning of the tournament in March that the duo had escaped a drugs test by not being selected for the World Cup.
The PCB had announced beforehand that 11 of its 15-man squad and seven reserves had passed domestic, pre-World Cup dope tests, but Shoaib and Asif were left out of the testing.