Dublin City Council Chief Executive Owen Keegan has told an Oireachtas committee that he gave absolutely no assurance, nor could he have, that all five Garth Brooks concerts would be licensed.

Speaking at the Oireachtas Transport Committee he said, he had been "supportive" of all five concerts, but did not give an assurance the five licences would be granted.

Mr Keegan appeared before the committee for a second time this week after Croke Park Stadium Director Peter McKenna gave conflicting evidence at his committee appearance.

Mr McKenna had told the committee that he would swear an affidavit that Mr Keegan gave him the assurance in February this year.

Five Garth Brooks concerts planned for Croke Park later this month are not now going ahead.

Ticketmaster yesterday began the process of refunding the 400,000 people who bought tickets for the gigs.

Mr Keegan said that an interview given by GAA Director General Páraic Duffy to RTÉ News in June, Mr Duffy had said eight concerts would be asking too much of the residents.

Mr Keegan said this totally undermines Mr Duffy's criticism of Dublin City Council for taking account of the concerns of the same residents.

He said he would have been supportive of five concerts when he had a conversation with Mr McKenna in February.

However, he said he would have made it clear that one key issue was that there were no issues arising from the three One Direction concerts.

The second crucial issue would have been to deal with the legitimate concerns of the residents, he said.

What emerged through the licensing process was failure to deal with those legitimate concerns, he said.

Committee chairman John O'Mahony said the aim of the committee was to establish the chain of events that led to the cancellation of all five concerts at Croke Park.

He said the whole episode had been an 'unholy mess' and there was a major conflict between the evidence of Mr Keegan and Mr McKenna.

Mr O'Mahony said who is right or wrong is not a function of the committee to decide and that may have to be decided at another forum.

He also said that clearly there had to be a more unified voice from residents and the GAA has to do more work on its relationship with them.

Elsewhere, the Minister for Transport has said it would be a very unhelpful and a dangerous precedent if the Government or politicians began to interfere with planning decisions.

Paschal Donohoe was responding to questions about the cancellation of the five concerts this afternoon.

He said Minister for the Environment Alan Kelly has now made it very clear that he will initiate a review of how licensing decisions will be made.

Mr Donohoe said it will be a quick review, which will put in place a good licensing regime for the future.

Ticketmaster has said the concert refund process is proceeding as planned.

It said about 190,000 of the 400,000 tickets had been refunded at close of business today.