Former Essendon coach James Hird says he accepts “a level” of responsibility for the supplements scandal that has rocked the AFL.

The Court of Arbitration for Sport this week upheld the World Anti-Doping Agency’s appeal against the AFL tribunal decision to clear 34 players of taking the banned substance thymosin-beta 4 while Hird was coach, handing 34 past and present players a 12-month ban.

In an ABC News 24 interview at The Ethics Centre in Sydney, Hird said he should have done more too prevent the situation that has now enveloped the club, cruelling its performance since 2102 and potentially ending careers.

“It is not just 2016 that it has wiped off (for the players) and potentially beyond but it has been 2013, 14 and 15 where they weren’t able to get the opportunity to play the football to their ability,” he told interviewer Tracey Holmes.

“I have a level of responsibility in that. I should have known more. I should have done more when the opportunity came.

“I feel extremely guilty for that and bad for that. I can only apologise for that. I made decisions in real time that in hindsight, I think were wrong.”

But Hird said others at Essendon made the situation worse and, while he had no objection to ASADA freely conducting its own investigation, he hinted the AFL had denied the club and the players a fair hearing.

“I don’t feel like a victim myself but those 34 players are victims of this situation, a situation that, at the first instance, is the responsibility of the Essendon Football Club,” he said.

“The football club and as a part that I had in it, has to put up its hand and say we made mistakes.

“Those mistakes were compounded by people in authority and outside the club.

“When I feel guilt, sadness, devastation for the players, I am also upset at the way the procedural fairness or process was enacted to deny our players procedural fairness and the football club fairness.”