The story
From characters the Dodgey Brothers (a pair of unscrupulous businessmen played by Stephen Blackburn and Geoff Brooks) in the 1980s and '90s Australian sketch comedy series Australia You're Standing In It and Fast Forward. The brothers' name is a homophone of the Australian term "dodgy" (meaning dishonest or unreliable), and the spelling of the name in figurative uses typically matches the slang term rather than the original spelling.
Etymology from Wiktionary, CC BY-SA 4.0.