Inspired by the James Bond film series, the name of the central character, Bob Fleming, references its literary creator, Ian Fleming.
This movie was re-titled 'Secret Agent Fireball' by American International Pictures for its American release in order to cash in on the box-office success of the James Bond film Thunderball (1965).
This espionage movie is not an official 077 spy movie in the Agent Dick Malloy Agent 077 Ken Clark series despite the fact that the agent's call number is referenced in some versions as 077. In fact, the character is referenced by two call numbers in the DVD: X117 and 077. The English language track numbers him as X117 while the Swedish subtitles number him as 077. As such, because of the X117 call number, the film also references the French spy OSS 117, making things particularly confusing.
In the United States, this movie was released in mid-January 1966 on a double-bill with another espionage movie, Spy in Your Eye (1965) [Spy in your Eye]. The American title banks on the worldwide release in December 1965 of the similarly titled James Bond's Thunderball (1965).
First of three Bob Fleming spy adventures and the first of two starring Richard Harrison as him. Harrison's second and final outing as Bob Fleming was in Killers Are Challenged (1966) [A 077: Challenge to the killers aka Bob Fleming - Mission Casablanca], first released about a year after this movie. Stephen Forsyth took over the role in the third and final picture, Furia a Marrakech (1966) [Fury in Marrakesh].