1943 D. Powell (new ed.) vi. 128 He had no secret mission to investigate the spy rings and unmask the Nazi agents.
1960 22 July 1/2 The spy-ring members began checking on the habits of people working in radar..establishments.
1980 22 Jan. 15/1 General Miyanaga, the leader of the spy ring, had been a Russian-speaking specialist working in intelligence for many years.