Michael Shayne, Private Detective is a 1940 American mystery film directed by Eugene Forde and starring Lloyd Nolan, Marjorie Weaver and Joan Valerie.

We see a subplot that out-of-work private detective Mike Shayne is hired by his friend, wealthy racing executive Hiram Brighton, to, while he's out of town, watch over his spirited daughter Phyllis, who gambles her money away and has begun dating underworld character Harry Grange, to the consternation of the father.

The key plot involves wealthy but shady Elliott Thomas who owned a horse, Banjo Boy.

In order to protect her from any kind of suspicion, Gordon framed Shayne, having conveniently seen him leave the casino earlier with Grange.

Eventually, Shayne correctly deduces what happened with the murder of Grange, and engineers a trap for Thomas in front of the police, at which point Thomas confesses the horse race plot, the death of Kincaid and throwing his body in the bay, and the murder of Grange, at which point the movie ends.