The 32-year-old is now under investigation by the Australian Sports Anti-Doping Authority AFP/Jonas |
The 32-year-old returned a positive sample for benzoylecgonine - the drug's main byproduct - in January and is now under investigation by the Australian Sports Anti-Doping Authority.
Football Federation Australia said his provisional suspension was mandatory under its anti-doping rules.
"While it is in place, Mr Larsen is prohibited from participating in the A-League and all other WADA (World Anti-Doping Authority) compliant sports," it said.
Ilso Larsen said he was "working closely with the PFA regarding my situation and awaiting the results from the B test" in a statement issued through Professional Footballers Australia.
"Until these results are received, I cannot make any further comments," he added.
"To our fans, please ensure the focus is on the team. It is a critical time in our season and they need you most of all."
Ilso Larsen joined Adelaide last year after a stint in Malaysia following a career spent mostly in Denmark and Germany.
"Adelaide United recognises the significance of the matter and wants to ensure our members, fans, and stakeholders that we will treat this with the utmost seriousness and sensitivity," the club said.
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