Double Demon is a 1951 Australian radio serial by Max Afford featuring his detective hero, Jeffrey Blackburn.

He wrote it after returning to Australia following a long trip to England, whereupon he signed a long-term contract with the ABC.

Afford knows, in which the detective knows who the criminal is, but—coming from another country—has no legal status to act."

The show might have been put on by the rawest bunch of amateurs getting their first chance on a country station.

His sturdy Australian, for instance, was a conventional stage caricature, but the landlady and her staff of freaks promise something better.