The ailing ex-president of the South American Football Confederation, Nicolas Leoz, has "nothing to hide" and denies the charges made against him in a sweeping US corruption probe of FIFA, his lawyer said Thursday.

"Mr Leoz has informed me he knows nothing about the crimes he is accused of and will certainly proclaim his innocence when the formal accusation arrives. He has nothing to hide," lawyer Raul Barriocanal told journalists.

Leoz, 86, was hospitalized in his native Paraguay Wednesday after learning of the case against him and the arrests of seven other top football officials in Zurich.

He is in a stable condition, Barriocanal said.

Another lawyer for Leoz, Ricardo Preda, said his client "can't go to prison" because of his poor health, including Parkinson's disease and heart problems.

Leoz led CONMEBOL, the South American federation, from 1986 to 2013, and is also a former member of FIFA's executive committee.

He is among the 14 football officials and marketing executives named in a US indictment charging them with racketeering, wire fraud and money laundering conspiracies across 24 years of corrupt schemes involving more than $150 million in bribes at FIFA.

A Paraguayan judge began processing the US extradition request for Leoz Thursday, asking prosecutors to set a date for an initial court hearing, judicial officials told AFP.