The appeal comes as the agency announced that the government has given protected status to one of the 12 so-far identified.
The underground station, discovered by a retired groundsman in the garden of a country house in Norwich, was part of mysterious secret wireless network operated by civilian agents.
So good was war-time Prime Minister Churchill’s plan that nobody has ever discovered where remaining wireless stations are located.
Churchill created the secret stations, either underground dug-outs or behind dummy walls in houses, mostly along the southeast coastal areas of Britain. Their task was to feed information to the military should Adolf Hitler have succeeded in invading Britain.
The recruits to “Churchill’s Secret Army”, also known as the “British Resistance Organisation”, had to verbally swear to secrecy, with one hand on a Bible. In some cases even their families knew nothing of the role that required them to leave their homes regularly at night.
The newly listed station in Norfolk is a rare example of a complete station, said Historic England. A bookcase conceals a secret wireless room and there is an escape tunnel for operators, should they were caught by German soldiers.
A spokesman for Historic England said: “Thousands of civilian volunteers were trained to use wireless stations in preparation for feared German invasion.”
The agency has appealed to the public for help in learning more about the mysterious underground network, asking: “was a member of your family part of it or do you think you know where one of the hidden wireless stations are?”
The spokesman added: “The increasing threat of German invasion and potential occupation prompted Winston Churchill to set up a secret army unit called GHQ Auxillary Units with a particular branch known as ‘Special Duties'”.
“This branch was made up of civilian volunteers living in the most threatened coastal areas in the country, trained to spy and report on German military activities from within occupied areas. These civilian spies communicated with the army by a secret wireless network.”
Government Heritage Minister David Evennett said: “This underground wireless station is a rare example of our Second World War heritage and deserves to be protected. It is a reminder of the often forgotten role so many civilians played in the war effort often acting in secret and undercover.” Enditem