Green’s Dictionary of Slang

a thief.

1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.
1914		E. Wittmann ‘Clipped Words’ in DN IV:ii 124: klep, from kleptomaniac. A thief.
1949		‘N.R. Nash’ Young and Fair 20: The kleps have started! [...] Already? What's been stolen?
2005		A. Lovejoy Acid Alex 100: One of them announced that I was a kleppie – a marrobaner.