William O'Brien was speaking to reporters after visiting Pat Hickey in hospital in Rio.
The 71-year-old President of the Olympic Council of Ireland was taken to hospital after his arrest yesterday.
He was complaining of chest pains and officers say they won't speak to him until his condition has improved.
Mr Hickey, who has temporarily stepped down from the OCI, is facing three charges including ticket touting, the formation of a cartel and ambush or illicit marketing.
There's no limit to how long he can be held before being charged – he could be sentenced to as long as seven years in jail – if convicted.
