FIBA secretary general Patrick Baumann has died, aged 51.
The Swiss had served in the role since 2002, while he was also a member of the International Olympic Committee (IOC).
Baumann suffered a heart attack at the Youth Olympic Games in Buenos Aires.
FIBA president Horacio Muratore said: "FIBA is forever indebted to Patrick. Without doubt, we would not be where we are today were it not for everything that he did."
IOC president Thomas Bach added: "We lose a young and sympathetic leader full of hope who was standing for the future of sport."