Europe's top Olympic official arrested in Rio over tickets sales

Mr Hickey, 71, is suspected of being involved in a scheme to sell tickets for higher than their face value, BBC reports.

He was taken to hospital as a precaution, and will probably stay the night there, police said.

The Olympic Council of Ireland (OCI) said he had stood down temporarily from his roles after being arrested.

Brazilian police said that when officers went to Mr Hickey's hotel room on Wednesday morning, they found his wife there with his Olympic credentials.

Mrs Hickey told them her husband had left Rio de Janeiro for Ireland at the weekend, they said.

With the help of the hotel they began a search and found Mr Hickey in the roomnext door, they added.

While police said they had reason to believe he was trying to escape, a video apparently of the arrest on the ESPN Brazil sports news website shows Mr Hickey answering the door naked to officers.

Police said the arrest was related to that of fellow Irishman Kevin James Mallon on the day of the Olympic opening ceremony.

More than 700 tickets organised in envelopes clearly marked for sale were found in a safe with Mr Mallon, Detective Ricardo Barbosa told the BBC.

Police estimate the potential profits of the alleged scheme at 10m reals (£2.4m; $3.1m).

The International Olympic Committee (IOC) said it would co-operate with any police investigation.

Irish broadcaster RTE reports that Mr Hickey faces three potential charges: facilitating ticket touting, forming a cartel, and "ambush" or illicit marketing.

In an interview with RTE last week, Mr Hickey denied any wrongdoing in relation to ticket sales.