Mr Walsh was charged with having 6.4 grammes of amphetamine and was acquitted in the District Court on November 26, 2008.
It was alleged in the District Court that Garda Walsh was off-duty when he was stopped by security men at the concert and refused to submit to a search after saying he was a garda. It was alleged a struggle ensued between him and a bouncer during which a bag containing the drugs was allegedly thrown and landed in a nearby bin. The bag was then allegedly retrieved by a security man.
Garda Walsh denied the bag belonged to him. When uniformed officers intervened during the incident, he was brought to the concert drugs tent where he refused to undergo a search.
The possession charge against him was later dismissed.
The Garda Commissioner, who had directed internal disciplinary proceedings be instituted against him before the District Court case, then ordered those disciplinary proceedings be continued.
It was alleged he breached discipline by refusing to submit to a drug search, improperly using his position as a garda for private advantage and using insulting and abusive language after refusing to be searched.
Another charge of discreditable conduct over alleged drug possession was withdrawn.
Garda Walsh then got leave to bring judicial review proceedings against the commissioner and the board of inquiry seeking to stop the disciplinary process as presently constituted, claiming unfairness on grounds it was based on a charge which had already been dealt with in the District Court.
The High Court ruled against Garda Walsh in 2010. He was dismissed on August 25.