A British scientist claims Allied spies considered spiking Adolf Hitler's food with female hormones in a bid to make him less aggressive.

The plan to sneak oestrogen into the Nazi leader's food never went beyond the planning phase.

It is one of several hare-brained schemes revealed by Professor Brian Ford in his book, Secret Weapons: Technology, Science And The Race To Win World War II.

Professor Ford, a fellow at Cardiff University and pioneer of popular science, revealed the British Government was serious about giving Hitler a sex change.

He says he uncovered the scheme while looking through stacks of recently declassified files from World War II.

They have come to light now because of the recent publication of documents not previously seen because of their sensitive nature.

Professor Ford says the UK also considered dropping boxes of poisonous snakes on Nazi troops, and bombing them with glue in an attempt to stick them to the ground.