MotoGP rider Andrea Iannone had his ban for doping with an anabolic steroid extended to four years on Tuesday because he could not prove contaminated meat was to blame.

The Court of Arbitration for Sport said its three judges dismissed the Italian rider’s appeal against an 18-month ban and upheld the World Anti-Doping Agency’s counter appeal requesting a four-year sanction.

The 31-year-old Iannone’s ban originally imposed by the International Motorcycling Federation was extended to December 2023.

Iannone cited eating contaminated meat for his positive test for Drostanolone at the Malaysian Grand Prix in November 2019.

The CAS judges found he was not able to prove “the precise type of meat he had consumed nor the origin of said meat.”

“Moreover, the panel found that neither Andrea Iannone nor his experts were able to establish specifically that there was an issue of meat contamination by Drostanolone in Malaysia,” CAS said in a statement.

Anti-doping rules place the burden of proof on the athlete to explain how a banned substance was present.

Athletes have had explanations of contaminated meat accepted after testing positive for clenbuterol in China and Mexico where it has been used in livestock farming.

A two-year ban could have resulted for a judgement of inadvertent doping.

However, the panel decided even if meat contamination was possible in Iannone’s case, he “has not been able to provide any convincing evidence to establish that the (violation) he committed was unintentional. “

Iannone had a contract to ride for Aprilia Racing Team Gresini.

His only MotoGP victory came at the 2016 Austrian GP.