They were accused of 'spying' for a foreign government.
a 'spy' camera/plane [=a camera/plane used for spying]
a 'spy' novel/thriller [=a novel/thriller about spies]
(..) "For her- all seven deadly sins!" "Death descends upon the city---!" The Book of Revelations "I put on this disguise to escape from the Thin Man... But for ten days your father's spy has been making even the workers' city risky..." "Only their hope for a mediator is keeping the workers in check..." (..)1927 Metropolis