The 98-year-old Brazilian, who headed FIFA from 1974 to 1998, responded well to treatment and was cleared by his doctors yesterday afternoon, said a spokeswoman at Samaritano hospital.

Havelange spent two months in the same hospital in 2012 with a serious ankle infection and heart and respiratory problems.

The news came as Brazil geared up for the opening match of the World Cup between Brazil and Croatia in São Paulo tomorrow.

Havelange, who competed for Brazil as a swimmer at the 1936 Berlin Olympics and water polo at Helsinki in 1952, played a key role in modernising football administration and making the sport a lucrative industry.

He was an influential member of the Rio de Janeiro bid team that won the right to stage the 2016 Olympics and Paralympics, the first to be staged in South America. 

Former FIFA President João Havelange has been released from Samaritano hospital in time for the start of the World Cup in Brazil tomorrow after six days ©Getty Images

But his later career was overshadowed by corruption allegations.

In December 2011, he resigned from the International Olympic Committee (IOC), where he had been a member since 1963, shortly before he was to face an ethics inquiry.

He was investigated over the collapse of FIFA's former sports marketing agency ISL, which went bankrupt in 2001 with debts of some $300 million (£178 million/€216 million).