Neus Català, who has died aged 103, was a lifelong fighter against fascism. A communist who had escaped over the Pyrenees at the end of the Spanish civil war, then joined the French resistance, she was eventually captured and sent to Ravensbrück, the Nazi death camp for women in northern Germany. She was then moved to the Flossenbürg camp, where she was set to work in the Holleschein munitions factory. Català was one of a group of women who sabotaged the bombs and shells being manufactured, by spitting in gunpowder or spilling oil in the machinery.

Her memories of the extermination camp, she said, were always in black and white, never in colour. She survived because of her determination and because “there was great solidarity among the women”. Català was critically ill when the camp was liberated in April 1945 (“We were just skulls with eyes”), but she recovered to continue her fight against fascism.

Disgusted that the allies had not overthrown Franco, in the postwar years she lived at Sarcelles, near Paris. She acted as a messenger for the Communist party’s underground work within Spain.

In the 1950s, disturbed at how the victims of fascism were too easily forgotten, she travelled all over France to find camp survivors. She compiled a list of the Spanish women in the camps. This led, in 1984, to the publication of Català’s book De la Resistencia y la Deportación: 50 Testimonios de Mujeres Españolas (Resistance and Deportation: 50 Testimonies of Spanish Women), which forced the question of historical justice into the public arena in Spain.

The daughter of Rosa Pallejà and Baltasar Català, Neus was born into a free-thinking family of small farmers in Els Guiamets, a village in the Priorat, southern Catalonia’s wine-producing and olive-growing country. By the age of 14, she was working in the fields: her first struggle was to demand equal pay for women in the grape harvest.

Neus joined the Communist Youth in the 1930s and remained a card-carrying communist all her life. In 1936, on the outbreak of the Spanish civil war, she moved to Barcelona, where she qualified as a nurse. By January 1939, when Barcelona fell to Franco’s troops, she was in charge of Les Acàcies orphanage at Premià, just north of Barcelona. In an odyssey through snow and bombs, she accompanied 180 orphans, mostly children of war victims, over the Pyrenees to France.

She, orphans and fellow exiles settled in Carsac, a village in the Dordogne, where she became involved in the maquis, resisting the German occupation. Català wrote: “In the civil war and the second world war, we women were not assistants, we were fighters.” In France she married Albert Roger. She was arrested in November 1943. After interrogation and torture in Limoges, she was sent to Ravensbrück in February 1944. Prisoner 27534, Català witnessed friends murdered. The seven companions of her hut all died. Her husband died at the end of the war, shortly after his release from Bergen-Belsen.

Living in France, Català got married again, to a Spanish exile, Félix Sancho, and she surprised herself by having two children, Margarita and Lluís – she had thought that the experiments conducted on women in Ravensbrück had left her sterile. In 1978, with the Francoist regime at an end, she returned to Catalonia, living in Rubí near Barcelona. She devoted her time to leading the Amical de Ravensbrück, an anti-fascist organisation of camp survivors, and to giving talks in schools.

All who heard Català speak remember her directness and passion. In the classrooms there was absolute silence. She liked to tell how she overheard a girl explain to another after one talk: “That’s the woman who defeated Hitler.” She was widely honoured in Catalonia: 2015 was officially Neus Català Year there. Her last political action came on 1 October 2017, when she voted in the disputed referendum in favour of Catalan independence.

In 2010, after a fall, she moved to an old people’s home in the village of her birth. She collaborated with Carme Martí in a novelised version of her life, Un Cel de Plom (A Leaden Sky, 2012), in which she explained: “I wanted to see it all. To see so as to explain. To explain what my eyes saw to everyone. Because it’s a duty. Because I survived and I have a moral duty to the women, so forgotten, who died in the death camps … I never, never cried before a Nazi. I only cried at night … They stole my sleep, but they never took my freedom or life.”

Félix died in 2001. Català is survived by her children.

• Neus Català i Pallejà, anti-fascist activist, born 6 October 1915; died 13 April 2019