It has always been viewed as one of Oxford’s most heartwarming wartime adventures.

The story of how a party of 125 Oxford children and 25 of their mothers braved the Atlantic in the summer of 1940 to live in foster homes in America left a lasting mark on those who took part.

With the Nazis at Calais and radio and newspapers talking about the imminent threat of invasion, the sons and daughters of Oxford University dons had been invited by members of Yale University to seek safe haven in America.

An act of incredible generosity, a display of the close bond between two great universities — or was it?

For a new book by the leading political columnist Jonathan Freedland presents us with an altogether more disturbing version of the famous wartime child rescue.

The motive behind the Yale offer, his readers learn, was, in fact, both chilling and sinister.

His book suggests the Oxford children and mothers were in fact lured to America by leaders of the eugenics movement, anxious to extract the children of Britain’s cleverest academics with a view to eventually repopulate a devastated Britain with “a superior” breed of human.

It must be said that the book is no carefully researched academic study, nor an explosive piece of journalism based on newly-released documents or bombshell confessions.

This shocking version of the children’s evacuation is presented in Mr Freedland’s latest novel Pantheon, published under his pseudonym Sam Bourne.

It forms the backdrop to the wartime thriller about a fictional Oxford don, James Zennor, who returns from rowing to find his wife and young son have disappeared and then follows them to Yale “to unearth one of the war’s darkest secrets”.

But while it is a work of fiction, the writer insists that story is “rooted in extraordinary facts”, arguing that serious questions remain to be answered about the Oxford-Yale episode.

The real story may also have a disturbing twist, he insists, and that behind the deed of supposed kindness may lurk a darker motive.

Mr Freedland lays his suspicions bare at the end of the novel in an author’s note, where he writes: “Some of those who were rescued have long wondered about the motives, not of their hosts, but the effort’s organisers: why were they singled out, was it perhaps their status as the offspring of the academic elite that made their plight particularly pressing?”

The 1930s fascination with eugenics is what lies behind his suspicions.

This involved the belief that society should encourage the strongest, fittest and brightest to have more children, while pushing, or even forcing, those deemed inferior or weak to produce fewer children, or none at all.

Remarkably, its disciples were not right-wing cranks and Nazi sympathisers but some of Britain’s greatest intellectuals.

Mr Freedland reels off a list of luminaries including Charles Darwin’s son Leonard, Bertrand Russell, George Bernard Shaw and John Maynard Keynes, while, according to the author, eugenics held great sway over the elites of pre-war Britain and America.

A new history of Yale suggests at the time of the evacuation eugenics was “red hot” at the Ivy League university.

But going on to suggest that the offer of a haven to Oxford children was, in fact, a plot to preserve the offspring of top British intellectuals, to effectively save the gene pool of those considered most worthy of preservation, risks causing offence to those with treasured memories.

Mr Freedland, who has written a weekly column for the Guardian since 1997, certainly recognises that people like the former Oxford Lord Mayor Ann Spokes Symonds, who was among the 125 who went to Yale, will be shocked.

He said: “It is important to say that I am certain that almost all the American families who opened their doors to the Oxford children did so out of the most altruistic motives.

“But what was going on in the minds of two or three organisers? That is what I’m asking about — not the motives of the families who opened their doors.

“I totally understand that people in their eighties and nineties only have the most fond memories of the people who took them in. I’m in no way challenging that. I’m questioning the motives of the people who set the scheme in motion.

“Tellingly, Dr John Fulton, of Yale Medical School, a prime mover behind the effort, said that the Yale Faculty Committee for Receiving Oxford and Cambridge University Children hoped to save ‘at least some of the children of intellectuals before the storm breaks’.”

Cambridge, Mr Freedland points out, had their own suspicions from the start.

“Cambridge rejected Yale’s offer, fearing that in the words of the then master of Pembroke College that ‘this might be interpreted as privilege for a special class’.”

Mr Freedland, who read PPE at Wadham College, Oxford, says he learnt much about the history of eugenics from his former tutor, Dr Michael Freeden, who was happy to play teacher again.

But his interest in the Oxford-Yale evacuation was sparked by a chance remark from the former Labour Cabinet Minister John Purnell over dinner.

“He mentioned that the mother of a mutual friend had been evacuated to Yale as a child and she had always wondered about the motive behind the evacuation. I made my mind up immediately that this would be the subject of the next Sam Bourne novel.”

He wasted little time in finding Juliet Hopkins, now 77 and an accomplished academic, to talk to her about her time at Yale.

But he would later discover something she had not know: the man who had taken her in, along with her brother and mother, whom she recalled as a kindly figure, was not only a geography professor but president of the American Eugenics Society.

But Mrs Spokes Symonds, 86, of Davenant Road, North Oxford — whose book Havens Across The Sea chronicles the wartime journey that she and the other Oxford children took in 1940 — has no truck with any super race plot.

She had dedicated her own book to the transatlantic foster parents and their families “who had opened their doors and their hearts to us”.

“I am a bit sad about it all,” Mrs Spokes Symonds told me. “It was really about the comradeship between academics. Many people wanted to take us. There were more offers of homes than there were children.

“Even if someone was a member of a eugenics society, it does not mean that there was this ulterior motive. People hearing about this master race idea, should remember it is a novel. It is not really what happened.”

  • Jonathan Freedland will be talking about Pantheon at the The Sunday Times Oxford Literary Festival (March 24-April 1) on March 26.

To book see the website www.oxfordliteraryfestival.org or call 0870 343 1001.