The Irishman, 71, was taken to hospital following his arrest, after requesting medical attention.

Brazilian police claim he was involved in a scheme to resell Olympic tickets at higher than their face value.

They said the scheme could have had profits of 10m reals (£2.4m; $3.1m).

Mr Hickey will be replaced as president of the European Olympic Committees - the body which brings together the 50 national committees across the continent - by his deputy Janez Kocijancic.

Resignation call

The Olympic Council of Ireland (OCI) said in a statement that Mr Hickey was stepping aside "until this matter is fully resolved" and would continue to co-operate and assist with all inquiries.

Acting OCI President William O`Brien said the council would "defend ourselves to the hilt" after the arrest of Mr Hickey.

However, a member of the Daíl (Irish parliament) said Mr Hickey`s decision to step down temporarily was not enough and called on the OCI president to resign.

Noel Rock from the ruling Fine Gael party told the BBC that, before his arrest, Mr Hickey had "stonewalled" questions asked of him by the Irish sports minister.

"He refused to answer straightforward, basic questions which were perfectly reasonable for the minister, who after all is responsible for the funding of the Olympic Council [of Ireland] to be asking of him," Mr Rock said.

"He also refused to have any kind of independent presence into any inquiry that may have taken place into the Olympic Council, into its corporate governance and into its commercial dealings, and that simply isn`t good enough," he added.

Mr Hickey, a former judoka, has been a member of the 15-strong executive board of the International Olympic Committee since 2012, making him a prime mover in the world of international sports.

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