The 95-year-old Brazilian was first admitted to hospital midway through last month with septic arthritis and had initially shown signs of making a recovery
The 95-year-old Brazilian was first hospitalised in Rio de Janeiro on March 18 suffering from septic arthritis.
Havelange had initially responded well to a treatment of antibiotics to control the infection but he suffered a relapse on Monday and is now struggling with respiratory and cardiac problems.
The former International Olympic Committee (IOC) member is no longer breathing unaided and Dr. Joao Mansur Filho of the Samaritano Hospital in Botafogo has described Havelange's condition as "serious" once more.
Havelange, who retains the title of an honorary president with Fifa, was forced to call time on his long administrative career within the game because of his health problems.