Former head of the Olympic Council of Ireland (OCI) Pat Hickey has now been discharged from hospital and taken into custody, according to local media.
It is understood he will now be questioned by police over allegations of ticket touting involving him and some of his associates.
Mr. Hickey faces charges of facilitating ticket touting, forming a cartel and illicit marketing. If convicted, he could spend up to seven years in prison.
The ticket touting scandal has cast a shameful shadow over the sportsmanship demonstrated by Irish athletes during the Olympics so far.