Formerly a Marconi radio engineer, where he solved the SATYR puzzle, Wright joined the Security Service as a technician in July 1955. In 1963 he was indoctrinated into a mole hunt code-named PETERS intended to identify hostile penetration of MI5. Wright achieved considerable expertise in his study of Soviet espionage and in April 1964 was selected to conduct the debriefing of Anthony Blunt, who had accepted immunity from prosecution for his betrayal of British secrets during and after World War II.
Wright pursued many of the leads provided by Blunt and was appointed a member of the Fluency Committee created jointly with Secret Intelligence Service to investigate possible moles. Although Wright interviewed numerous suspects, he obtained only one complete confession, that of Leo Long, who had been run by Blunt and had served in MI14 during the war, before he went into the film business. Blunt obtained partial confessions from Jenifer Hart, Iris Murdoch, Bernard Floud MP, and James McGibbon, but none were ever prosecuted. After retiring from MI5 in 1973, as one of a dozen assistant directors, Wright moved to Cornwall to breed horses, but was retained by MI5 as a consultant on a part-time basis, before finally leaving altogether at the end of January 1976 and emigrating to Tasmania later the same year.
When Prime Minister Margaret Thatcher asserted in November 1979 that all the evidence of hostile penetration of MI5 could be attributed to Blunt, he believed she had been misled by the Security Service and collaborated with the veteran Fleet Street journalist Chapman Pincher to document his investigations in Their Trade Is Treachery. Disappointed with the book, Wright then coauthored SpyCatcher with a television producer, Paul Greengrass, which resulted in a lengthy legal action brought by the British government in Aus-
tralia to prevent publication. The final House of Lords judgment upheld the principle of the lifelong duty of confidentiality owed by MI5 personnel to their employer, but meanwhile the litigation had made the book an international best-seller. Wright died in Tasmania in April 1995, having written two further books, neither of which enjoyed SpyCatcher’s success.