Design of an exploding chocolate bar
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Drawings of WW2 exploding chocolate bar bombs discovered

30 September 2015 Last updated at 07:50 BST

Drawings of wartime booby trap bombs, including an exploding chocolate bar and devices intended to sink ships have been rediscovered after 70 years.

The designs were made by a young artist called Laurence Fish, for MI5's counter-sabotage unit.

Nick Higham has had an exclusive look at them.