Former senior FIFA official Eugenio Figueredo has been taken from custody to a clinic to be treated for a heart problem.
Figueredo had been remanded in custody since being extradited on Thursday to his native Uruguay by Swiss justice authorities.
Prosecutor Juan Gomez said 83-year-old Figueredo, a former FIFA vice-president and South American confederation president, had admitted during a hearing on Thursday to receiving bribes as part of a fraud and money laundering probe.
Figueredo, who is alleged to have taken bribes in exchange for commercial rights to tournaments, is also the subject of a US extradition request as part of a US justice probe into corruption affecting football.
Figueredo was vice-president of the South American confederation CONMEBOL from 1993 to 2013 and president from 2013.
He was one of seven officials arrested in Switzerland in May at the request of US prosecutors.
Swiss authorities approved requests from both the US and Uruguay for his extradition.