It lies beneath a grand London mansion, owned by the Queen and leased to the government. It contains around 39,000 bottles of wines and spirits. For years, details of what was in it were shrouded in secrecy, even though it has been funded by the British taxpayer.

Welcome to the Government's wine cellar. Lancaster House is down the road from Buckingham Palace. It sits well in such a prestigious neighbourhood. However, the ornate grandeur of the public rooms stops at the door to a fire escape, which takes you down to the basement and to a service corridor. A key is turned in a large wooden door. Step inside and the temperature drops considerably. A short alarm goes off to let everybody know there is a visitor.