The esteem which the islanders nevertheless held for Cook caused them to retain his body. Following their practice of the time, they prepared his body with funerary rituals usually reserved for the chiefs and highest elders of the society. The body was disemboweled and baked to facilitate removal of the flesh, and the bones were carefully cleaned for preservation as religious icons in a fashion somewhat reminiscent of the treatment of European saints in the Middle Ages. Some of Cook's remains, thus preserved, were eventually returned to his crew for a formal burial at sea. (on Wikipeda )

It's a complex story.