Trainer Paul Murray has pleaded not guilty to eight charges relating to elevated cobalt levels found in Group Two winner Alma's Fury.
Stored samples taken from Alma's Fury after he won the Apollo Stakes in February 2013 and finished second in the Doncaster Prelude in April that year showed levels higher than the allowed 200mg.
The reading in the plasma sample from the Apollo Stakes was 391 in the first sample and 315 in the reserve.
Alma's Fury returned levels of 890 and 940 in the tests on the urine sample from the April race.
The inquiry, which reconvened on Monday has been adjourned to a date to be fixed.