'I suppose you're referring to Fluker,' I told him, and he looked at me in stunned amazement when I explained that he was one of my old oppoes.2012, Tony Orchard, Here's to our Far-Flung Empire:
“It's all right, chaps, the decorator's come. This 'ere is me old ’oppo Ginger Vernall.”2016, Alan Moore, Jerusalem, Liveright, published 2016, page 53:
oppo
noun
Etymology Clipping of opposition, or of opposition research as a whole.
1
Government, PoliticsUS, Informal Research into one's opponent's family, friends, and past, which aims to uncover activities or interests which embarrass or discredit them.