This is the only movie in the "Inspector Wears Skirts" franchise that was not produced by the Golden Harvest studio. This is also part of the reason that it being the third film in the franchise is relegated to a subtitle within the movie's title.
Golden Harvest, production company behind the first two films in the series, decided to pass on this sequel due to being displeased with the amount of comedy in the script overtaking the action sequences. Not wanting to compromise the script to add more action, series director Wellson Chin and screenwriter Man Choi Lee were forced to seek independent financers to make the film. This is the reason why the English language title is only "Raid on Royal Casino Marine" and not "The Inspector Wears Skirts 3". This is also the reason why this third entry is not included in home media box sets and collections of the franchise as Golden Harvest does not allow films they've produced to be featured in sets alongside films produced by other studios.