Test result 'unusual', says expert

LONDON - Chris Froome's positive test for excessive levels of the asthma drug Salbutamol at this year's Vuelta a Espana was unusual but dehydration or metabolism could have played a part, an anti-doping expert said on Wednesday.

Tom Bassindale, a forensic scientist who works at Britain's Sheffield Hallam University, said further tests under controlled conditions could clear Britain's four-time Tour de France winner if it showed other factors at play.

"He gets the chance to prove that either his metabolism is particularly different from everyone else's or that dose has a bigger excretion into his urine compared with the standard," he told Reuters.