Bob Baffert has insisted he is innocent of any wrongdoing after announcing Kentucky Derby winner Medina Spirit has tested positive for 21 picograms of the anti-inflammatory drug betamethasone.

The Hall of Fame trainer told reporters at a press conference on Sunday that the findings – which are above the permitted raceday level of 10 picograms in Kentucky – were a “gut punch”.

He said: “All I can tell you is that betamethasone, even though it’s an allowed drug, a therapeutic medication, we did not give it, my veterinarian or anyone here.

“Medina Spirit has never been treated with betamethasone, (and) I cannot believe that I’m here before you guys. I never thought I’d be here. Yesterday (Saturday) I got the biggest gut punch I’ve had in racing, for something that I didn’t do, and it’s really disturbing – it’s an injustice to the horse.

“I don’t know what’s going on in racing right now, but something’s not right. I don’t feel embarrassed, I feel like I was robbed.

“We are going to do our own investigation – we are going to be transparent with the racing commission, like we have always been. We are going to show them everything – and one thing about California, everything is documented every day, what the horses get.

“This horse was never treated with that, and he’s a great horse, he doesn’t deserve this – he ran a gallant race and to me. I just feel like this last 18 months, what I’ve gone through, it’s like all of us right here, just imagine going to work every day and they test you every day for these levels, these contamination levels and they told you if you tested positive you were going to be fired. That’s the way I feel.

“I do not feel safe to train – it’s getting worse and to me going forward how do I enjoy the training? How do I move forward from this, knowing that something like this can happen and it’s just a complete injustice?

“But I’m going to fight it tooth and nail, because I owe it to the horse; I owe it to the owner and I owe it to our industry.

“I’m not a conspiracy theorist, I know everybody is not out to get me, but there is definitely something wrong. Why is it happening to me?”

Baffert added: “We know we didn’t do it, and that’s the thing. We didn’t have anything to do with it. I don’t know how it got in his system, if it’s in his system or was there a mistake – we are going to get to the bottom of it.”

Ridden by John Velazquez, Medina Spirit made all in the Churchill Downs showpiece to beat Mandaloun by half a length, giving Baffert his seventh victory in the ‘Run for the Roses’.

Officials at Churchill Downs said Baffert would be suspended from making entries at the track and that, if the findings are upheld, Mandaloun would be promoted to first place.

A statement read: “It is our understanding that Kentucky Derby winner Medina Spirit’s post-race blood sample indicated a violation of the Commonwealth of Kentucky’s equine medication protocols.

“The connections of Medina Spirit have the right to request a test of a split sample, and we understand they intend to do so. To be clear, if the findings are upheld, Medina Spirit’s results in the Kentucky Derby will be invalidated and Mandaloun will be declared the winner.

“Failure to comply with the rules and medication protocols jeopardizes the safety of the horses and jockeys, the integrity of our sport and the reputation of the Kentucky Derby and all who participate.

“Churchill Downs will not tolerate it. Given the seriousness of the alleged offence, Churchill Downs will immediately suspend Bob Baffert, the trainer of Medina Spirit, from entering any horses at Churchill Downs Racetrack. We will await the conclusion of the Kentucky Horse Racing Commission’s investigation before taking further steps.”