O. H. "Harry" Turner was an Australian physicist who worked in defence science and intelligence and pressed his government for a scientific investigation of unidentified flying objects. He trained at the University of Western Australia and, during the Second World War, took supplementary radar courses, then called radio location, at Sydney University, according to the researcher Bill Chalker, who knew him in later life. He is best known today for a 1971 intelligence paper on UFOs that American disclosure figures began citing in 2026.

His involvement began in 1954, when the Royal Australian Air Force's Director of Air Force Intelligence asked him for a scientific appreciation of the air force's early case files. Chalker told ABC News that Turner compared the Australian reports with American data and concluded that a residue of cases represented evidence of extraterrestrial craft. He recommended concentrating on radar and physical-trace cases, and the report was largely ignored. At the end of 1954 he went to Britain's atomic energy research establishment at Harwell, and from 1956 to 1964 he was stationed at Maralinga as the Australian health physics representative during the British atomic trials.

Turner then moved to the Joint Intelligence Bureau, later the Joint Intelligence Organisation, where Chalker says he headed the nuclear science section of its scientific and technical intelligence directorate and served as liaison to air force intelligence. From 1968 he wrote memos urging a serious study, proposed a scientific "rapid intervention" team, and in 1969 helped the air force with a wave of reports around Perth, after which his access to its UFO files was withdrawn. His superiors were unpersuaded: in February 1970 the directorate's head wrote that he was not convinced the subject had enough scientific intelligence content to justify diverting Australia's limited resources.

On 27 May 1971, signing as head of the Nuclear Branch, Turner sent the organisation's director two papers under the heading "Scientific and Intelligence Aspects of the UFO Problem." The first set out his interpretation that American agencies had publicly debunked the subject while studying it covertly; the second drew on Jacques Vallée's catalogue of landing reports. The director, R. W. Furlonger, instead proposed a small trial of investigations by the Department of Supply, which was never adopted. The file was released through the National Archives of Australia in 2008.

Chalker first contacted Turner in 1982, interviewed him repeatedly, helped arrange a 2004 video interview, and received much of his personal files. When David Grusch urged the public in June 2026 to read the 1971 paper and it reappeared as file CIA-UAP-019 in PURSUE UFO Files Release 03, Chalker published a "reality check": the paper was a draft and "Harry's view," not official policy, and its "crash program" wording meant a rapid effort, not crashed craft. The skeptic Mick West called the document "largely not new" and its author "a UFO enthusiast." A clip circulating in September had Turner recounting that his former superior Richard Durance, then army attaché in Washington, was shown radar data during the 1952 Washington sightings. Turner remains the clearest case of an Australian government scientist who argued from inside the defence establishment for a sustained UFO study, and his papers remain central to Australia's official UFO history.