Prince de Merode, who has been an IOC member since 1964, acted as Chairman of the committee's Medical Commission for the majority of his time at the IOC.
The Belgian-born member was instrumental in the IOC's stance against doping within sport. He died aged 68.
Said IOC president Jacques Rogge on hearing the sad news: "The Olympic Movement has lost an exceptional man. Through his charisma and his convictions, the Prince de Merode was a fervent defender of Olympic values throughout his life.
"He was, in particular, one of the pioneers in the fight against doping, creating the IOC Medical Commission in 1967. His ideas and energy helped to begin an unceasing fight against doping and any activity damaging the integrity of sport. We have all lost a remarkable colleague, a humanist at the service of sport."
The International Olympic Committee (IOC) is mourning the passing of one of its long-standing members, Prince Alexandre de Merode.
