She was 54 when she first got to know her mother, but Antonia Radas was one of the luckier ones. Taken away when her mother, Carmen, was imprisoned after the Spanish Civil War for her father’s Republican links, Mrs Radas’s adoptive parents lied to her, telling her that she had been abandoned, and changed her name to stop relatives tracing her. Mother and child were finally reunited in 1993, 18 months before Carmen died.

Now 71, Mrs Radas is among an estimated 30,000 children who were separated from their parents on the orders of General Francisco Franco. Many of them never knew who their real parents were.

Now, there may be hope for some of those seeking answers after a Spanish judge asked provincial courts across the country to investigate the fate of these “lost children”.

Baltasar Garzón, a crusading champion of human rights, has claimed that Franco and 34 henchmen were guilty of the systematic killing or disappearance of at least 114,000 people during and after the civil war.

Among the victims were children of Republicans who were adopted by Franco sympathisers to prevent them coming under the influence of Marxism. Others, whose families fled abroad, were lured back to Spain under false pretences. “Child refugees were also kidnapped in France by the repatriation service of the regime and put in state institutions,” Judge Garzón wrote.

“They were made to pay for the sins of their fathers. Frequently they were ill treated.”

Xenu Ablana, 80, was sent to a centre run by Franco’s Social Aid charity for children of Republicans, where he was taught allegiance to the Falange, the party allied to Franco.

“I know all the Falangist hymns, all the prayers of the Church. They brain-washed me against my father, against true democratic society,” Mr Ablana told The Times.

“I never had any toys, never knew anything about girls until I escaped. I was robbed of my childhood. I am still looking for my childhood now.”

Despite Judge Garzón’s request, Mr Ablana, from Santiago de Compostela, in northwest Spain, does not hold out much hope of justice after all these years. “The courts are still run by Francoists. These people have a lot of influence,” he said. Others have searched for years without tracing lost sons, brothers or sisters.

Emilia Girón, the wife of a leftwing guerrilla fighter, searched fruitlessly for her son, Jesús, who was taken from her in prison. She died last year aged 96.

In an interview with Spanish documentary-makers before her death, she said: “I know I gave birth to him. They took him to be baptised but they never brought him back. I never saw him again.”

Desperate to find loved ones, some have turned to DNA testing. MarÍa José Huelga, 84, paid for tests on five women in France, Belgium and Spain in an attempt to find her sister, MarÍa Luisa. None was successful.

Judge Garzón began investigating the cases but last year withdrew, conceding jurisdiction to regional courts, who now have the authority to decide whether or not to take up these controversial cases.

Julián Casanova, a historian, claims that the aim was to “reCatholicise” the children of “Reds”. He said: “The Church was responsible for the theft of these children, from Red families. It wanted to purify them.”

Antonio Vallejo-Nájera, a leading psychiatrist, was asked by Franco to carry out a programme to cleanse leftwingers’ children and transform them into supporters of the regime. With echoes of the Nazi “master race” ideology, Dr Vallejo-Nájera wrote a manual called The Eugenics of Hispanicity and Regeneration of the Race.

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