One of the most discussed legends addressing Jagannath's mixed origins, examined at length by historians of Odisha such as Hermann Kulke, tells of a king named Indradyumna who learns of a wonder-working blue image called Nila Madhava, worshipped in secret in a remote forest by a tribal chieftain named Vishvavasu of the Sabara people, an indigenous community of the region with religious practices distinct from and older than mainstream Brahminical Hinduism. The king sends emissaries to find the image, and by various stratagems, in some versions marrying his daughter to the tribal priest's family, in others simply by persistent searching, eventually gains access to it, only for the original image to vanish and be replaced, through further divine instruction, by the logs of wood from which the current wooden Jagannath images are said to derive.
Scholars generally read this story as a fairly transparent, and unusually self-aware, narrative memory of an actual historical process: an originally tribal or indigenous cult object being absorbed, reinterpreted and ultimately controlled by an incoming Brahminical royal and priestly establishment, with the legend itself preserving, rather than erasing, an acknowledgment that the deity's worship did not begin within the mainstream Hindu tradition that now administers it. This kind of layered absorption, in which a regional or tribal sacred object is drawn into a larger religious system while memory of its earlier origin persists in the legends the new custodians tell, is a documented pattern across South Asian religious history, and Jagannath's case is among the more openly discussed instances precisely because the repeatedly renewed images keep the cult's unconventional origins visibly unresolved rather than smoothed over.