In 1959 he documented a sighting of an unidentified object in the sky and began collecting data on this and other fringe phenomena. Rex Gilroy spent many years researching the "Ancient Archaeology" of Australia, and claimed through thousands of artifact finds that the Phoenicians established many colonies in parts of Queensland in Australia, including port and dockside facilities. 

Gilroy claims that thousands of years ago, Australia must have had many inland tributaries and river networks, and the Phoenicians sailed upon them. Pyramids, such as the so-called Gympie Pyramid have also been claimed to have been found in Australia by Gilroy, who insists that they reveal that at some period in the distant past there existed a vast network of pyramids across the Pacific Asia Region, which he equates to the civilization and continent of Lemuria. Sonar mapping has shown there was no such landmass in the Pacific.