The father-and-daughter training combination of Terry and Karina O’Sullivan are facing a second prohibited substance case.
Racing Victoria stewards are continuing investigations into a high cobalt reading taken from Darragh in a pre-race urine sample at Ballarat in November.
The O’Sullivans, based at Stawell in rural Victoria, have also been charged after dexamethasone, a short-acting corticosteroid, was detected in a post-race urine sample from Dandy Gent on September 2.
Dandy Gent finished second behind Sir Laszlo in a 2400m race.
The charges will be heard by the Racing Appeals and Disciplinary Board at a date to be fixed.