Leoz, the President of CONMEBOL from 1986 to 2013 before he resigned citing health reasons, had been under house arrest since mid-2015 in Paraguay’s capital Asunción, fighting extradition in connection with the scandal.

He died of heart failure in hospital on Wednesday (August 28), medical sources and local media reported in Paraguay.

In November 2017, a judge in Paraguay approved the extradition of Leoz to the US to face charges. 

The former FIFA vice-president, a close ally of disgraced former FIFA President Sepp Blatter, was accused of accepting millions of dollars in bribes from marketing companies in exchange for television and marketing rights, but denied any wrongdoing.

Key Government witness Alejandro Burzaco, the former chief executive of sports-marketing giants Torneos y Competencias, claimed Leoz had stolen $5 million (£4.1 million/€4.5 million) from FIFA that was meant for CONMEBOL from revenues generated by the Club World Cup.

The Argentinian executive also stated he had bribed more than 30 people and had given out around $160 million (£132 million/€145 million) in illicit payments.

His early testimony had claimed Leoz was one of three South American officials, along withh former FIFA senior vice-president Julio Grondona and Brazil's Ricardo Teixeira, who were bribed to pick Qatar in the controversial vote for the 2022 World Cup.

Burzaco, who accompanied the three officials to the December 2010 vote in Zurich, said it was widely known they would all back Qatar.

But Grondona allegedly told him that Leoz had instead voted for Japan and South Korea.

The FIFA corruption scandal led to the conviction and imprisonment of Leoz's successor as CONMEBOL President Juan Ángel Napout and ex-Brazilian Football Confederation head José Maria Marin.

Leoz's funeral took place in Asunción yesterday.