Dead Man's Evidence is a short film from 1962 starring Conrad Phillips, who was a very familiar screen presence in those days. The screenplay was written by Arthur La Bern, an interesting character whose most famous novel, Goodbye Piccadilly, Farewell Leicester Square, was filmed by Hitchcock as Frenzy. La Bern was a pretty good storyteller who was also a journalist specialising in true crime.
And this is a story which, I suspect, was sparked by a real life mystery, even though I've not managed to find any discussion of the film which supports my theory. But in 1956, the mysterious disappearance of a frogman called Commander "Buster" Crabb made headline news. The puzzle has never been solved, though according to some theories Crabb was a spy who became a double agent. My guess is that the case inspired La Bern, even though his story moves in a fresh direction after the body of a diver with connections to the intelligence services is washed up on an Irish beach.
Conrad Phillips plays David Baxter, an intelligence officer who is asked to look into the death of the diver. Could the body belong to a friend of Baxter's, who was suspected of being a double agent? The only clue is a ring that appeared on the dead man's finger, but which quickly vanished. Can someone be trying to conceal the identity of the deceased, and if so, why? Baxter pretends to be an insurance investigator, but a local journalist, a woman photographer and her mysterious boyfriend all become curious about his activities.
The story zips along rather nicely, and there's a decent plot twist. The Irish setting is also well done. Phillips was a charismatic actor, even though he never became a really major star. He befriends a charming and seemingly naive young woman, a limited role but well played by Jane Griffiths; I'd never heard of her, but it seems that she died all too young. Overall, this unpretentious film is definitely worth watching. .