A RARE example of one of World War II’s strangest secret weapons — an exploding rat — has been unearthed.

British scientists stuffed dozens of the dead rodents with explosives, detonators and fuses. The idea was for French Resistance fighters and Special Operations Executive agents to infiltrate armament factories and leave the rat corpses around the boiler rooms.

It was hoped the Germans would throw the vermin straight into the furnace, triggering an explosion and wreaking havoc in Nazi-occupied France.

But the first batch of 100 rat bombs was intercepted by the Germans in 1942 and the plan was never put into practice

However it caused a great deal of confusion among the Germans who assumed there were thousands of others and went on an epic hunt for them.

Now a rat bomb that belonged to British agent Jack Dickens is going up for auction in New York for £1,500.

Mr Dickens, who went by the name of Maurice Ledain, was dropped behind enemy lines to carry out acts of sabotage. But the rat was found and ended up in storage at a French police station. Other secret weapons for sale on December 6 include a fountain pen that turns into an assassin’s metal spike. It would have been used by an SOE agent to overcome a German guard. It is valued at £3,000.

There is also a pocket-sized wooden coffin containing wire used for strangling someone. These were left on doorsteps by the Resistance as a warning against collaborating with the Germans.

Auctioneers Bonhams said: ‘Some of the disguised weapons are quite chilling. But they highlight the do-or-die nature of SOE agents who operated in Nazi-occupied Europe.’

The items are being sold on December 6 in New York.