The touring West Indies cricket squad have been banned from training and are confined to their hotel rooms after breaching managed isolation rules on several occasions.
Director-General of Health Dr Ashley Bloomfield said their breach came to light yesterday, which was the 11th day of their 14-day stay.
They were gathering in groups in corridors, sharing food, chatting, and not staying in their rooms - as they were obliged to.
The team was warned, but some members were found to have met outside the rooms after that.
A further investigation found CCTV footage of team members breaching rules on other occasions too. Bloomfield could not say how early on.
"I was more surprised than anything. They clearly knew what the expectations were, they had signed up to this before the tour.
"My understanding is they had done a tour of the UK earlier on in the year so had already been through this experience."
Bloomfield said they were warned and all their privileges had been revoked.
"We immediately rescinded their ... privilege around getting together and training.
"They are no longer allowed to train together, they are all required to remain in their rooms."
They were due to train today and tomorrow.
He said it was up to the medical officer of health to decide when the team could be allowed to leave quarantine.
"We have indicated that it may be necessary for them to stay longer. We won't hesitate to do that if we think there is any risk to the public."
All members of the team have tested negative twice, he said. Their day 12 testing results are yet to come in.
Their governing body has been notified to take disciplinary action.
Bloomfield said it was not within his purview to send the team back home.