Daring spies who broadcast from behind enemy lines

Owning just one of them in World War Two carried the death penalty, But Ian Keyser has more than a dozen - ensuring a piece of secret history is brought out into the open. So what are they?

They are, of course, spy radios - used to send messages back to base from behind enemy lines. And decades later, much of the collection is still in use. Tony Green has this special report.