Chambers recently invited me below ground at the Brompton Road Tube station in West London, which he intends to turn into a restaurant and museum in time for the 2012 Olympics.

BBC: Reawakening the Underground

He said the Tube driver told passengers he was unable to stop at West Ham station due to "police investigations".

BBC: London football violence probed

The version found in a house in Hawthorn Street in west Belfast is an older model with a wooden stock instead of the metal tube in later versions.

BBC: Worn and rusting rocket launcher still capable of killing