The black and white footage entitled The Sun Always Lives shows boys fighting with live ammunition as shells and smoke bombs explode around them.

The film was made in 1977 and features members of the Communist party’s Young Pioneer youth movement and was filmed at one of their summer camps in the resort of Lubmin am Greifswalder Bodden.

It was intended to be show in schools "to instil true Socialist patriotic values in the young".

The film lasts for 21 minutes with the young participants mimicking the military manoeuvres of the People’s Army of East Germany.

At the end of the film a live shell from one of the mini-tanks hits a wall. At this point the voice-over for the film says: "Show your soldierly face for the Socialist Fatherland as these brave warriors do!"

Hubertus Knabe, 50, director of the museum at the former Stasi museum in Hohenschoenhausen in Berlin, where dissidents opposed to the regime were caged in often appalling conditions, was shocked by the film.

He said: "This is a perversion of childhood by the Stasi of a kind I haven’t seen before. All kids played with toy guns but this was meant to turn them into child soldiers of the sort who have raped and killed in Africa in recent years. To let little kids loose with real guns to prove a political point seems about as sick as it can get for me.

"The intention of the Stasi was to sharpen up the potential for violence of the next generation at an early age. The readiness for violence was prepared with the mother’s milk, as it were."