John Gavin played secret agent OSS 117 in this Eurospy picture and when it came to re-cast the character of James Bond after George Lazenby's departure from the part after On Her Majesty's Secret Service (1969), Gavin initially won the role of James Bond to first appear in Diamonds Are Forever (1971). At the last minute Sean Connery agreed to return as Bond for the sixth time in a two-picture deal and at an astronomical salary for the time. Producer Albert R. Broccoli insisted that Gavin be paid the full salary called for in his contract.
In 1970, in the UK, this was commonly the supporting feature on a double bill with the initial release of the final film in the "Doctor" series, Doctor in Trouble (1970).
A gigantic device hanging from a helicopter releasing a gas poisoning policemen in this movie is a clear reference and copy of the gigantic hanging magnet from You Only Live Twice (1967).