Likable actor Dennis O'Keefe made a couple of films in England in the '50s. "The Diamond Wizard" from 1954 is his baby all the way - he wrote the original story using a pseudonym (Jonathan Rix), he directed it, and he starred in it.O'Keefe plays Joe Dennison, a Treasury Dept. investigator in England trying to find a gang who stole a million dollars from a treasury vault and also killed his partner. One of the criminals apparently is in England to buy fake diamonds, though they realize he must be coming by ship because he as of yet isn't in England.The Scotland Yard inspector, McClaren, is working with Dennison on the case while also searching for Dr. Eric Miller, an atomic scientist who has disappeared. His daughter, who came to England to join her father, has a broach with phony diamonds, made by her father. So is he somehow involved with the thieves? This isn't a very interesting film until the end, where the location is an incredible castle. The whole end moves at a great pace, is suspenseful and atmospheric. I wish the whole movie had been that way. It's odd in the way it starts out as somewhat light, with both men competing for the missing man daughter's affections, and then has this big ending. Both lead actors, O'Keefe and Philip Friend (the inspector) are very charming.The story is derivative, but I love the idea of the phony diamonds -- there are so many of these today, and they even mention Moissan, whose product, Moissanite is available (and expensive) today.

IMDb Trivia: One of the "75 Most Wanted" films listed by the British Film Institute as "Missing, believed lost".I saw this film on Netflix, so apparently it is NOT lost--at least not any more.Dennis O'Keefe plays a Treasury Department agent who has been sent to Britain. This is because there may be an organization that has learned to produce perfect diamonds--ones that are so perfect it could destroy the market. The trail leads to a scientist--a scientist who has disappeared. Although the chances are ridiculous, the wanted man's daughter just happens to be a lady that the Treasury man was dating! He's afraid to tell her about everyone's suspicions about her father and he and Scotland Yard are baffled.This is a decent British version of film noir. While it's not quite as dark as many films in the genre, it is tough and violent and enjoyable. However, it does start off very slowly--so keep watching and don't give up on this one--it's worth it.If you do watch a couple things you should note. First, at one point in the film they talk about a remarkable fake diamond being produced in 1924. While it was believed in 1954 that this was true, apparently this was a hoax and that part isn't mentioned in the film. Second, when O'Keefe is chased by a truck he's knocked onto the cobblestones. Watch closely--these cobblestones bounce--revealing they are clearly props.

Also known as THE DIAMOND is directed, written and stars Dennis O'Keefe. American federal agent Joe Dennison travels to London in search for clever fugitives suspected of stealing a million dollars from a U.S. Treasury vault. Dennison will team up with Inspector McClaren(Philip Friend)of Scotland Yard and do double duty helping his British counterpart. The two detectives share in the hunt for a missing atomic scientist Dr. Eric Miller(Paul Hardmuth), who is believed to be deeply involved in a ring pushing fake diamonds. Dennison and McClaren, who Dennison calls Mac), get the idea that solving both crimes may rest with the scientist's daughter Marline(Margaret Sheridan). Plot and pace are top notch. Other players: Michael Balfour, Gudrun Ure, Seymour Green and Alan Wheatley.

Using the non-de-plume of Jonathan Rix, his grandfather's name, Dennis O'Keefe hied himself over to England and sold this story (with screenplay by John C. Higgins) and ended up as the star and (credited) director of this film that was merely a slight---primarily geography and accents---remake of at least a half-dozen American B-westerns with the plot gimmick revolving around a heroine's scientist father being kidnapped and forced to counterfeit something---diamonds, in this instance---for a gang of crooks. One of the readily available horses-and-sagebrush versions is 1941's "Dude Cowboy" from RKO with Tim Holt, Marjorie Reynolds and Byron Foulger essaying the roles taken here by O'Keefe, Margaret Sheridan and Paul Harmuth. Give "Dude" the edge over "Diamond" on the strength of Ray Whitley's songs.