The Racing Integrity Unit have begun an investigation following a positive test result for prohibited substance cobalt from the stable of former champion jockey Lance O'Sullivan.
In a shock announcement, the RIU confirmed this morning they are investigating three horses from Matamata's famous Wexford Stables operated by O'Sullivan and training partner Andrew Scott.
This is the first cobalt positive returned in New Zealand. A number of leading Australian trainers are currently under investigation, including Peter Moody, who prepared champion mare Black Caviar. There is no suggestion Black Caviar was ever tainted by an illegal substance.
Cobalt is a prohibited substance in horse racing at a level of over 200 micrograms per litre in urine. It is a naturally produced substance in horses, but rarely above 10 microgrames per litre of urine.
Stable runner Quintastics tested positive after winning at Matamata on 11 March.