Researchers in Germany have chanced upon a Stasi ID card that was issued to Vladimir Putin during his time as a KGB officer in East Germany at the end of the Cold War.

The curious find was made at the Stasi documentation centre in Dresden, which archives the activities of East Germany's all-powerful secret police. Archivists were following up an unrelated media inquiry when they found Mr Putin’s ID card among documents on officer training in the eastern city.

Before entering Russian politics, Mr Putin spent four years as an agent of the Russian KGB in Dresden in the 1980s and witnessed the collapse of the communist state first hand.

Konrad Felber, the director of the Stasi archives in Dresden, told Bild newspaper that the Stasi ID would have given Mr Putin broad access to the secret police’s offices.

“It really is a mini sensation,” Mr Felber said. “This meant that he didn’t need to let anyone know that he was working for the KGB.”