Olympic boss Pat Hickey has stepped down temporarily from as role as President of the Irish organisation after his arrest in Brazil.
The development capped an extraordinary day in this year's controversial Olympics which began with Hickey (71), the president of the Olympic Council of Ireland (OCI), being arrested in his dressing gown in his Rio hotel by Brazilian police.
The wife of Pat Hickey lied to detectives when they arrived at his hotel room to arrest him, saying he had returned to Ireland, police in Rio de Janeiro said.
Police executed a warrant yesterday morning to detain Mr Hickey on suspicion that he was aware that tickets from the OCI had ended up with THG Sports, a British company not accredited to sell them.
He is accused of plotting with others to sell tickets above face value in a scheme that authorities say would have netted about $3m (€2.7m) in profits.
Officers arrived at the Windsor Marapendi Hotel near the Olympic Village in Rio de Janeiro at 6am yesterday to find his wife, Sylviane, alone in bed.
However, her husband's possessions were still in the room, Brazilian police said.
When asked where he was, Mrs Hickey said he was not in the room.
Police eventually found Mr Hickey, wearing his dressing gown in another, otherwise empty room registered in the name of his son.
Mr Hickey, in his capacity as president of the OCI, is in Rio to attend the Olympic Games.
"This morning we arrested the president of the Olympic Council of Ireland at a hotel in Barra da Tijuca," said Ronaldo Oliveira, the head of specialist operations with the civil police.
"Our detectives arrived at the hotel early. We worked with the hotel. When we arrived at the room that was registered to him, we found only his wife, who was sleeping. She did not want to help. She lied, saying that he had already gone home to Ireland.
"But we saw that his shoes, socks and his open suitcase were still in the room. We then found him in another room registered to his son. There were hardly any personal possessions in that room.
"He is 71 and the doctor in the hotel said he was shaken. He was taken to hospital for tests before he will be released to police."
Detective Aloysio Falcao said: "Hickey has been involved in the Olympics for more than 20 years and we believe he knew everything that went on."
Police seized the Dubliner's passport, Olympic credentials, Olympic tickets, three laptops, two mobile phones and a return air ticket dated August 22.
It is understood Mr Hickey was taken to Hospital Samaritano Barra near the Olympic Park. He is expected to remain there until at least tonight.
He told police he has a heart condition, but it is understood his blood pressure is satisfactory. He is being guarded by police and is effectively under house arrest.
The OCI confirmed last night that an arrest warrant had been issued by Brazilian authorities.
However, in a statement it said: "Contrary to reports, Mr Hickey complied fully with the terms of the warrant. Mr Hickey was taken ill as this warrant was served and was taken to hospital as a precautionary measure.
"In light of this morning's developments and his ill health, Mr Hickey has taken the decision to step aside temporarily as president of the OCI and all other Olympic functions (IOC member in Ireland, EOC president, ANOC vice-president) until this matter is fully resolved.
"Mr Hickey will of course continue to co-operate and assist with all ongoing inquiries."
Mr Hickey, his wife and Russ-ian president Vladimir Putin met in Moscow in 2014 at a special ceremony after the Winter Olympics in Sochi.
Last month, Mr Hickey admitted to being "shocked" when an international report called for an outright ban on Russian Olympians at the Rio Games following the latest in a series of independent investigations set up by the World Anti-Doping Agency (Wada).
The report was produced to deal with allegations of state-sponsored doping at the Sochi Games, and the dark practices of Grigory Rodchenkov, former head of Moscow's anti-doping laboratory.
Mr Hickey asked what mandate authorities "have to lead an international call for a ban of another nation in the Olympic family".
In the end, a host of Russian athletes across a range of sports were allowed to compete in Rio.
Brazilian police have also obtained court orders for the preventative detention of three suspects, all directors of Pro 10 Sports Management, the Irish accredited seller of Olympic tickets who police believe divert- ed the tickets to THG.
The three are former Irish footballer and St Patrick's Athletic manager Eamonn Collins; another Irishman, Ken Murray; and UK national Michael Glynn. Mr Collins refused to speak to the Herald at his Clondalkin home last night.