Tony Brooks was recruited by the Special Operations Executive (SOE) largely because of an act of personal initiative in France. Subsequently, despite his youth and inexperience, he became one of SOE’s most successful agents, methodically combining caution with imagination – seldom natural bedfellows.

He specialised in sabotage of railway systems, but it was his meticulous reception arrangements for airdrops of arms and explosives that won him the confidence of SOE’s London headquarters, the Royal Air Force and the resistance fighters so supplied.

Brought up in Switzerland and fluent in French, he was working in his father’s timber business in the French Jura at the time of the Franco-German armistice in June 1940. He met by chance a British private soldier who, having avoided capture at Dunkirk, was gamely making for the Pyrenees on foot, reading the maps inside French telephone boxes and following road signs. Brooks had heard of an escape line to England being set up in Marseilles, so he put the soldier in touch with a local contact and then followed him out, reaching England in late 1941.

Although he was only 19, SOE snapped him up as ideal material, trained him in silent killing and sabotage techniques, briefed him on the French trade union structure and dropped him blind – that is without an arranged reception party – into the Garonne on the night of July 1-2, 1942, shortly after his 20th birthday.

His first task was to establish a circuit of local agents, then to assess the likelihood of persuading French railway workers to sabotage traffic northwards from Marseilles to Lyons and Toulouse, to be exploited as opportunity offered.

His only contact, made in a Toulouse café by exchange of a codeword, turned out to be a former acquaintance, and the two set up one of SOE’s most successful circuits, codenamed Pimento. Having no radio link with SOE in London, Brooks formed a courier line using trusted railway staff to deliver messages to a communication point in Geneva. For local cover he coopted another family friend, a Montauban garage owner, for whom he worked as a mechanic. This conveniently allowed him to travel widely in the South, ostensibly to collect parts from vehicles abandoned in the 1940 exodus south.

Knowledge of trade union practices, his excellent French and persuasive manner gave Brooks ready access to workers on the Marseilles-Toulouse-Lyons rail network. This became their framework for sabotage after the German occupation of southern France in November 1942, following the Allied landings in French North Africa, when the railways became critical to German resupply and – after the Allied invasion of Normandy in 1944 – their movement northwards.

Brooks had a narrow escape when the train from Toulouse on which he was travelling entered Lyons. The platform was thick with Gestapo but the Pimento agent waiting for him pretended to be a plain-clothes French policeman, bundled him into a police car and spirited him away.

During 1943 Brooks arranged for more than 30 airdrops of weapons and explosives. In fact he received more weapons than he could usefully deploy to the Maquis youths who had taken to the hills to avoid conscription for German labour camps, most of whom became partisans.

Abrasive axle grease and explosives were used to dislocate the railways in the Garonne until Brooks returned to London by a Hudson aircraft in August 1943 for rebriefing and to get married. He was awarded the Military Cross for the sabotage he had organised or undertaken during his first period in occupied France.

He returned in January 1944 to direct sabotage operations against the railway yards at Lyons. During his absence the Pimento circuit had suffered some losses of French sub-agents to the Gestapo but without serious damage to the circuit as a whole. He had two further narrow escapes in the months before and shortly after the Normandy invasion. In May, an airdrop container of grenades exploded on impact, leading to a vigorous search of the area by a German SS unit, obliging him to hide up a tree for 24 hours.

More alarming was his chance arrest during a street spot check in Lyons in late July, by which time the Allied invasion had heightened the alertness of the occupying forces. He was unarmed and carrying no incriminating documents but the 72,000 French francs in his pocket aroused suspicions. His German interrogators kept him without food for 48 hours before questioning him but were unable to break his original cover story of being a mechanic from Montauban. He explained the francs as the price of a suit on the black market he was hoping to buy. He was released – and the cash returned.

Sabotage by the Pimento circuit resulted in the derailment of every train carrying German troops or equipment at least once in its journey from Marseilles to Lyons after D-Day (June 6, 1944). Consequently, the journey of key elements of the Das Reich 2nd SS Panzer Division from Toulouse to the Normandy battlefield took more than two weeks.

By mid-August 1944 the position of German troops in southern France had become so perilous that Brooks decided to break cover. Planting a Union Jack on the bonnet of a car he had requisitioned, he led attacks on enemy transport vehicles using phosphorous grenades while his Pimento partisans engaged withdrawing troops in street ambushes. He was awarded the DSO for his service in France in 1944.

After the war Brooks helped to wind up SOE and transferred to the Secret Intelligence Service (MI6). He served in Sofia between 1947 and 1950. In 1952, after ten years of constant stress and domestic pressure of a failing marriage, he resigned and returned to the French company which had employed him before the war.

During this period he remarried. But by 1956 the scars of wartime had faded and Brooks was bored by commerce. By good fortune SIS was at that time looking for someone with Brooks’s experience and skills in the context of the Suez invasion and civil unrest in Cyprus. He was reemployed in Cyprus, and successive governors sought to prolong his service there.

It was a trimphant return, but the rest of his service was something of an anticlimax. He was a distinct success, not unsurprisingly, in Paris between 1959 and 1963. But spells in London and Geneva were less happy. It was as if the preoccupation with secrecy which had kept him alive in wartime France had come to dominate his view of peacetime operations.

His last few years in the service were spent on secondment to the Security Service (MI5). He finally retired in 1977 and returned to a business career.

Anthony Morris Brooks was born in Essex in 1922. He was educated at Chillon College, near Montreux, and at Felsted School in Essex.

His first marriage, in 1943, was dissolved and he is survived by his second wife, Hélène (Lena), whom he met in Lebanon. There were no children of either marriage.

Anthony Brooks, DSO, MC, officer of the SOE and of the Secret Intelligence Service, was born on April 4, 1922. He died on April 19, 2007, aged 85