Godolphin trainer Mahmood Al Zarooni will stand before a British Horseracing Authority disciplinary panel on Thursday afternoon after he was charged with doping horses and bringing racing into disrepute.
Eleven out of 45 horses initially tested positive for banned substances, but the BHA have since confirmed that a further four horses had illegal drugs in their systems.
Despite Al Zarooni's revelation, the trainer will not face charges on the additional horses as they were not tested positive during the probe.
A statement from the BHA said: "Information provided by Mahmood Al Zarooni to the Investigating Officers has revealed that, in addition to the 11 horses which tested positive and were named on 22nd April, a further four horses were administered one of the two prohibited substances. Those horses are: Comitas, Sashiko, Vacationer (all Ethylestranol) and Tearless (Stanozolol). These horses were under the care of Mr Al Zarooni but had not been subjected to testing.
"As these additional horses were not tested and no positive samples exist, no charges are brought under (C)50 and/or (C)55 in relation to them and as such the trainer remains facing the original 11 counts of this charge at this stage."
The hearing is scheduled for 2.30pm in London tomorrow.
Danielle Joynson
