For the first time, an exhibition in Berlin has released never-before-seen images of disguised spies from former communist East Germany, showing them wearing wigs and moustaches.

The Ministry for State Security, commonly known as the Stasi, was the official state security service of East Germany. Headquartered in East Berlin, Stasi was widely considered as one of the most effective intelligence and secret police agencies in the world.

The Berlin exhibition has been put together by German artist Simon Menner who collected the pictures from the secret Stasi archives.

"These were used during courses on how to dress up and blend into society. They seem pretty absurd now, but it was meant seriously -- this is evil stuff," Reuters quoted Menner stating.

The photos show the spies dressed in a variety of costumes. Menner collected the pictures using a "network of informants" and scanning through the classified Stasi files. In the process, he discovered Polaroid photos made by Stasi agents when they secretly searched peoples' houses on the hunt for evidence they might be betraying the communist state.

Check out the unique images of the disguised Stasi spies below: