While scholars debated, the hoax claims were also being challenged outside science|scientific circles. In 1987, the Philippine Congress held a four-month-long public investigation into the hoax claims, during which Elizalde arranged for a Tasaday woman to be present to support the original claims. The investigation concluded in favor of the original claims and denounced the possibility of a hoax. In 1988, President Corazon Aquino also conducted an inquiry and announced that the Tasaday were genuine and had nearly been victimized by unscrupulous scholars and businessmen who wanted their logging|timber- and mining|mineral-rich land. After the investigations, the Philippine National Museumand other official organizations began listing the Tasaday among the Philippines' indigenous people.
The Tasaday are a small group of indigenous people from the tropical rain forests of South Cotabato in Mindanao who allegedly lived a Stone Age life. Throughout the 1970s the Tasaday received world-wide fame, and then again in the 1980s when Oswald Iten purportedly discovered that they were a hoax masterminded government officials close to President Ferdinand E. Marcos.
Up until the mid twentieth century, the Tasaday as of 1971 could recall historical contact with two other local groups (known to the Tasaday as the Sandukasand the Tasafangs), apparently with similar lifeways to the Tasaday and also from the forest. Contact with the modern world (e.g. metal, cloth and cultivated foods) was not known to the 1970s Tasaday until the mid-20th century (exact date unknown, possibly the 1950s), when they met and began sporadically trading with Dafal, an itinerant member of various Philippine tribes including the Manobo Blit, Ubu and T'boli. (Note that these peoples, generally living outside the forest, were known to and at least somewhat familiar with the modern world at this time.) It is noteworthy, and helpful in comprehending the Tasaday's long-standing isolation, that many tribal peoples of Mindanao avoid the deep forest due to superstitions or beliefs.