It is a saga that sounds like a John le Carré spy thriller, but played out at the top end of Danish politics. The former defence secretary, Claus Hjort Frederiksen, is emotional as he recalls when his ordeal started. "I parked my car in front of my house, and as I turned off the engine, two police officers jumped out of their car, came up to me and informed me that I was being charged with a very serious crime that could lead to 12 years in prison". It was December of 2021.