Green’s Dictionary of Slang

1. pertaining to the police.

1971		J. Mandelkau Buttons 143: I contemplated ripping off a pig landrover.
1987		(con. 1967) Bunch & Cole Reckoning for Kings (1989) 45: Ain’t no way to bribe them pig MPs at the wire.
1990		Crow Dog & Erdoes Lakota Woman 120: All these Indians and they can’t total one lousy pig car!
1994		I. Welsh ‘Stoke Newington Blues’ in Acid House 41: Ah’m gaunny git sorted wi this pig gear.
1996		P. Howard The Joy (2015) [ebook] We went down to the pig station and [...] into this interview room.
2000		N. Griffiths Grits 97: Fuckin pig spy, that cunt is like.

2. (US) pertaining to the white Establishment.

1973		J. Godey Taking of Pelham One Two Three 145: [A] blueprint for revolutionary terror drawn up by the Central Committee of SWAM to terrorize the running dogs of the repressive and exploitative pig ruling class of America.
1982		(con. 1970) J.M. Del Vecchio 13th Valley (1983) 364: This pig shit. This white man’s war.