Green’s Dictionary of Slang

ducks and geese n.

[rhy. sl.]

(Aus.) the police.

[Aus]S.J. Baker in Sun. Herald (Sydney) 8 June 9/5: Detective Doyle has about a dozen rhyming slang words in his list. For example: [...] ‘ducks and geese,’ police.
[Aus] ‘Whisper All Aussie Dict.’ in Kings Cross Whisper (Sydney) xxxiv 4/4: ducks and geese: Police. Shortened to ‘duck and’.
[Aus]R. Aven-Bray Ridgey-Didge Oz Jack Lang 7: She was thinking of her lazy silvery moon, the ducks and geese, and the cost for the use of the drum in the cracker joint she operated from.
[Aus]Tupper & Wortley Aus. Prison Sl. Gloss. [Internet] Ducks and geese. Rhyming slang for police.
[Aus]Pete’s Aussie Sl. Home Page [Internet] ducks and geese: the police.