They were among an ingenious collection of devices - many of which would have delighted James Bond - provided for agents of the special operations executive (SOE), the covert group set up to help resistance movements carry out sabotage and subversion, or as Churchill put it, "set Europe ablaze".

Boffins at the SOE's laboratory at Aston House in Stevenage, Hertfordshire, produced an array of items in which the agents could conceal codes and messages - often written on silk - in collar studs, matchboxes, toothpaste tubes, and sponges. "Bundles of faggots" were provided to camouflage wireless sets.

One-man submarines



With minute attention to detail, SOE's section Q, the title Ian Fleming subsequently gave to Bond's source of exotic equipment, researched current continental fashions, both men's and women's, including different styles of sewing on buttons. It developed a small electrically propelled canoe, called "sleeping beauty", and one-man submarines. And it applied crude Freudian psychoanalysis to the behaviour of agents in the field.

For agents in the far east, SOE backroom agents developed a sandal, described in files released yesterday at the public record office as "carrying a sole bearing an imprint of a Japanese shoe or native foot... They are easy to wear and the track left by the wearer leaves faithful imprints hiding all traces of the intruders having been other than Japanese or local natives."

The devices are explained in a handbook marked "Most Secret" given out to secret service agents.

Weapons outlined in the book included reproductions of Balinese woodcarvings stuffed with explosives. "Native agents" were encouraged to pose as hawkers along quaysides and sell the booby souvenirs to Japanese troops as they embarked.

Agents also disguised hand grenades as sugar beet and hid weapons and radios in suitcases with false bottoms. They hid explosives in plaster logs, books, tins of food, fruit, cigarette packets, driftwood, and fake coal of 140 different shapes. The "coal" fed into a furnace would explode "with sufficient violence to damage the boiler or at least to render the profession of locomotive driver highly unpopular", the writer of one report commented.

Other top secret devices included itching powder - "the greatest effect is produced by applying the powder to the inside of the underclothing," according to the records - cream which frosted clear glass in five minutes, a deodorant that threw dogs off the scent, and "suicide pills" small enough to conceal in a ring. One version had a special coating, harmless unless chewed, so the pill could be hidden in the mouth. "The coating will not dissolve in any liquid; it is therefore no use as a lethal tablet for 'bumping off' purposes," the SOE said.

For agents operating in Italy, false bottles of chianti, half-filled with wine, were made from celluloid and covered by transparent green paint, to look like glass, hiding a detonator.

Exotic device



But the most exotic device was the "explosive rat". A hundred of the rodents were procured by an SOE officer posing as a student needing them for laboratory experiments. The rats were skinned, filled with plastic explosive, and sewn up. The idea was to place a rat among coal beside a boiler. When they were spotted, they would immediately be thrown on to the fire, causing a huge explosion.

That was the theory. As one of the SOE files records: "This device caused considerable trouble to the enemy, but not quite in the way that was intended." The Germans intercepted the container of dead rats before they could be used for "operational purposes". But all was not lost. According to an SOE report, their discovery had an "extraordinary moral effect": the rodents were exhibited at all German military schools, prompting a hunt for "hundreds of rats the enemy believed were distributed on the continent".

SOE concluded: "The trouble caused to them was a much greater success to us than if the rats had actually been used."

The files reveal that cipher training got off to a bad start with some agents' traffic described as an "anagrammer's paradise". The failure of young agents to destroy one-time pads led to SOE drawing up a report entitled Ciphers, Signals, and Sex.

"If the action of cutting away and destroying a code is regarded through the eyes of a psychoanalyst," says the report, "it becomes obvious at once that this action to many people will symbolise to the unconscious mind the act of organic castration."

On torture - to which many captured agents were subjected - the report notes that "sadomasochism is one of the strongest of all unconscious emotions, and that neurotics go to incredible lengths in order to attain the libidinal situation that pain may arouse in them".

The report also addresses the issue of "talkativeness". It says: "The whole act of receiving droppings of stores from the sky, and exploding trains, are rich in sexual symbols to the unconscious mind, and talkativeness on the part of the agent is bound up with very many more emotions than simple narcissism."

Whitehall and service chiefs were initially sceptical about the SOE and what they called "a cloak and dagger party which did not amount to any real force in the general field of operations against the enemy".

However, it soon won the support of Churchill and other agencies - "a great deal of useful assistance was obtained in the study of burglars' methods from MI5 and Scotland Yard", notes one file released yesterday.

It adds that "one of the last acts in SOE was an attempt to ensure that in any future conflict or international crisis where special operations were required... subversive operations should have [government and ministerial] support".

Recruits included some German PoWs, called "bonzos", with anti-Nazi sympathies, as well as "undesirable elements" - an issue that was to strain relations between SOE and MI5.

SOE recruited about 10,000 men and 3,200 women. Of about 6,000 agents who were sent into occupied Europe, north Africa, and Asia, 850 were killed in 36 countries.

Top of the props made to go bang

Chianti bottle

"The Chianti bottle is made of thick celluloid, and is in two sections. The lower section is bowl shaped, the top section represents the neck and shoulders of the bottle, and has the base of the neck closed by means of a diaphragm of celluloid so that the neck may be filled with wine to complete the camouflage when the bottle is assembled. Each section is filled with PE [plastic explosive]... [and later] a detonator.

The two sections are fixed together and the joint sealed with acetone and buffed up, the inside of the celluloid having first been treated with transparent green paint, so that when the two portions are fixed together the whole takes on the appearance of green glass as used in wine bottles. Next the raffia cover is attached to the bottle together with authentic labels. The effect is that of a genuine bottle of Chianti."

Explosive pump

"A hollow brass cylinder filled with explosive and fitted with a pull switch, is pushed inside the barrel of a bicycle pump [and] the safety pin withdrawn. The enemy's pump is replaced by the explosive one and his tyres deflated."

Balinese carvings

"These are faithful reproductions of the famous Balinese wood carvings, [but each is] cast in solid explosive [and] mounted on a wooden base, and equipped for initiation by a time delay. It is intended to use these through native agents posing as hawkers frequenting the quaysides, and selling them to Japanese troops about to embark."

Explosive coal

"A hollow cast of a piece of coal is made in two sections. The interior is filled with plastic explosive... The coal is finished off with a coat of black shellac garnished with coal dust."