THE AFL Anti-Doping Tribunal resumed on Monday, with ASADA calling a medical expert to give evidence in its case against 34 past and present Essendon players.
 
ASADA lawyer Malcolm Holmes, QC, called the specialist to give evidence on substances that are the subject of infraction notices. The witness was then cross-examined by counsel for the players.
 
The hearing, which is being held behind closed doors in the Victorian County Court, will continue on Tuesday.
 
ASADA is alleging the 34 players and one support person, no longer employed by Essendon, breached the AFL Anti-Doping Code through the use of the banned peptide Thymosin Beta-4.
 
In December, ASADA lost a legal battle to have two of its key witnesses, biochemist Shane Charter and compound pharmacist Nima Alavi, testify at the hearing.
 
Charter and Alavi have given evidence to ASADA but refused to sign sworn affidavits backing the authority's allegations that the players were administered the banned drug Thymosin Beta-4 as part of Essendon's 2012 supplements program.
 
When Holmes concludes his submission, lawyers for the players will argue the players were given a legal version of thymosin, thymosin alpha-1 or thymodulin.
 
The hearing is being held in private after a ruling by Tribunal chairman David Jones on December 8 last year.