The article said it was "adverse analytical finding of amphetamine"
Another blurb:
"Mr Stewart has the right to request and attend the analysis of his B sample.
A Provisional Suspension imposed by the FIM does not in any way prejudge the question as to whether an anti-doping rule violation under Article 2 of the FIM Anti-Doping Code has actually been committed.
This question will be addressed by the FIM International Disciplinary Court (CDI) when it adjudicates on the merits of the case. Mr James Stewart is provisionally suspended with effect from 20 June until further notice.
Under the World Anti-Doping Code and the FIM Anti-Doping Code, the FIM is unable to provide any additional information at this time."
And, why take amphetamines? To improve performance in endurance.
Amphetamines current medical use is limited, with only Dexedrine (dexamphetamine sulphate) currently available for use in the treatment of narcolepsy - where the patient cannot help suddenly falling asleep.
So. it is possible that Mr. Stewart has a legitimate prescription.
We will just have to wait and see...