In what is potentially a major blow to their case, The Australian Sports Anti-Doping Authority’s application to subpoena two witnesses to appear at an AFL tribunal over the Essendon Football Club’s supplement regime has failed.

The tribunal involving 34 current and past Essendon players is scheduled to go ahead on Monday.

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The players are facing bans of up to two years if they are found guilty of taking the banned peptide Thymosin beta-4 during the 2012 season.

The Australian Sports Anti Doping Authority (ASADA) had wanted to compel Shane Charter and Nima Alavi to appear at the tribunal to give evidence.

But today the Supreme Court rejected its application.

ASADA alleged that Mr Alavi compounded the banned peptide given to the players and Mr Charter, a biochemist, imported the substance.

Both men have provided interviews to the authority but refused to testify in the case.

ASADA boss Ben McDevitt earlier said that while he would prefer the pair to be there, the anti-doping body had a strong case without them.

“Despite media reports to the contrary, while it is my preference for potential witnesses to front the tribunal in person, I do not believe it is essential,” he said.

Despite McDevitt’s comments, today’s court decision means players are likely to object to some evidence being admitted at next week’s tribunal hearing, on the basis that the witnesses cannot be cross examined. This could potentially derail ASADA’s case against Essendon.

On Monday the tribunal’s chairman David Jones ruled the media and public would not be allowed to attend the hearings in order to protect the players’ privacy.