美國是否已回收四種外星物種？新的說法進一步推動了UFO故事的發展。

UFO researcher John Stewart claims the U.S. government has recovered and stored remains of at least four alien species since 1945. He asserts that these entities are held in clandestine facilities and studied by a secret group, urging the government to move beyond vague admissions and provide full disclosure of autopsies and living beings to the public.