The Policing Authority says it’s "simply not good enough" that a number of gardaí cancelled emergency calls.
It’s emerged a further 53 emergency calls were cancelled without the proper process being implemented.
That was despite new procedures being implemented after thousands of calls were previously cancelled.
Chairman of the Policing Authority Bob Collins told Newstalk Breakfast it’s unacceptable.
He said: “If there is a saving grace in this, it is that of the 53 calls, none were from someone who was in imminent danger or experiencing domestic violence.”
Mr Collins noted the “great majority” were house alarms or "non-threatening" calls, but said "that's not the point".
He said: “It’s less important than the fact that all the safeguards that were introduced following the wholesale, unwarranted cancellation of calls… that someone or some group of people decided they could bypass those regulations or take it on themselves to cancel calls.
"It's simply not good enough.”
Mr Collins said this is not a question of extra training - saying he "will begin to scream” if he hears more calls for training.
He said: “I agree there is continuing work that needs to be done to ensure people understand the meaning of anxiety, threat and fear and the circumstances that can cause people to ring 999… but on this particular instance, there is nothing to defend it and nothing to justify it.”
The Policing Authority chair says he doesn't believe reform of An Garda Síochana is impossible but noted it is “particularly difficult” to change the culture of a policing service.
He added: “I’ve no doubt that the Commissioner is absolutely committed to change and to reform within the organisation - but there is a very considerable amount of work to be done.”
Senior gardaí yesterday told the Authority they have been reassured that the handling of 999 calls had improved within the force.
Garda Commissioner Drew Harris said the 53 calls would likely have been cancelled if forwarded to a supervisor, but dispatchers appeared to have "taken it on themselves" to cancel the calls.
He said it was "very disappointing" and shocking that the further call cancellations had happened, despite a big focus within the force on the new processes.