Italy captain Fabio Cannavaro failed a dope test after taking a medicine that contained the banned substance cortisone, it was revealed on Thursday.
The former World Player of the Year was allegedly stung by a wasp and took a medicine that contained cortisone on August 29.
He requested an exemption on the grounds that it was emergency medication but his request was missing a document and while awaiting a decision he was subjected to an anti-doping test, which returned a positive result.
His club Juventus claimed he took nothing more than an anti-allergy medicine and that it was necessary to prevent a potentially fatal outcome.
"In response to the news relating to an inquest opened by the anti-doping prosecutor into Fabio Cannavaro, Juventus's medical team underlines that it acted within sanitary prescriptions and moral rules to intervene in a case of emergency following the worsening of the clinical situation as a consequence of an insect sting," said a statement on Juventus's website.
"On such an occasion, vital medical therapy is given to prevent potential complications, even fatal ones."
The Italian Football Federation (Figc) claimed they were immediately made aware of the situation as Juventus had sent a copy of the exemption request to their doctor just before Cannavaro joined up with the national team ahead of matches against Georgia and Bulgaria on September 5 and 9.
Cannavaro is currently on international duty once again, preparing for Italy's last two World Cup qualifiers against Ireland in Dublin on Saturday and then at home to Cyprus on Wednesday.
Cannavaro is suspended for the Ireland match but was expected to return to the team he captained to World Cup glory in 2006 for the Cyprus game.
He is due to be interviewed by the Italian Olympic Committee's (Coni) anti-doping prosecutor Etorre Torri on Friday morning in Turin.
Coni released a statement on its website explaining the circumstances of the positive test without revealing if any action has been taken against the player.