Police met the venue days before the birthday party, where it was agreed that "all future under-18 discos would be cancelled", according to the report.

But on 22 September the Welsh Ambulance Service was called to a report that a 13-year-old "had been drinking, was losing consciousness". In all, three children were treated at the scene and two were taken to hospital to recover.

"There was concern that children may have also taken cocaine and ketamine," said the report.

CCTV footage of the children being treated outside the venue was shown to the committee behind closed doors because it was considered too distressing for public viewing.

Emma Priestley, owner of EJP Entertainment, which runs the pub and club, apologised and told Friday's review hearing she had been let down by a former senior member of staff.

Ms Priestley told the hearing she was distressed by the "disturbing" footage, according to the report.  She is reported to have said:

"The protection of children is extremely high on my priorities.

"It is not how we run our operations and, obviously, I trusted the people to run these operations and I have been very let down by certain people.

"I can't apologise enough."

North Wales Police licensing officer Aaron Haggas claimed the company was not taking collective responsibility and attributing the blame to one or two members of staff.

He said the children treated by the paramedics were "simply asked to leave".

"At one point, a member of the public assists the children as they lie outside on the bench," he said.

"Further on, when the police arrive, a child can be seen to be lying face down on the floor outside the front of the premises.

"It is bad enough that the party has gone ahead.

"The biggest concern is the response from the premises.”