Green’s Dictionary of Slang

(Aus.) stop it! look out!

1955		‘No. 35’ Argot in G. Simes DAUS (1993) n.p.: haste (V. imperative, only) Desist! (an urgent warning to cease illegal activity because danger threatens; originally it was probably an injunction by the cockatoo to hasten away at the approach of the law. Now, it corresponds to the schoolboy’s ‘Cave!’.
1959		Baker Drum 116: Haste! Look out! Mainly used in criminal jargon. Whence haste it! to cease some activity equivalent of Stop it! Synonymous is ace it!
c.1972		Parramatta Jail Gloss. 3: haste, Stop immediately or you’ll be sprung.