Too Naked for the Nazis has nosed ahead of Reading from Behind: A Cultural History of the Anus to be named the oddest book title of the year.

The Bookseller’s annual Diagram prize, which has been running since 1978, rewards books not for their content, but for the strangeness of their title. Won in previous years by the scarily-specific Greek Rural Postmen and Their Cancellation Numbers, the seemingly instructive How to Poo at Work and the eyebrow-raising Big Book of Lesbian Horse Stories, this year Alan Stafford’s Too Naked for the Nazis triumphed in the public vote.

A biography of the lives of Wilson, Keppel and Betty, an eccentric music hall trio known for a “sand dance” routine performed in Egyptian costume, which scandalised Nazi leaders in 1930s Berlin, Too Naked for the Nazis was originally going to be called Walk Like Three Egyptians.

“It’s very difficult coming up with a title,” said Stafford. “I came up with Too Naked for the Nazis because it’s quite central to what the book is about. In 1935, they were dancing in Berlin, and the story goes that the Nazi high command objected to their sand-dancing act because of the nudity involved – Wilson and Keppel’s bare legs.”

He submitted his book for the prize himself, and pronounced himself delighted to have won the traditional “passable bottle of claret”, which goes to whoever submits the winning entry.

“People kept saying to me that it was a good title, and I was aware of the Diagram prize. I thought if I don’t put it in, and someone else does, I’ll get nothing,” he said. “Wilson, Keppel and Betty were not a serious act – they were very much in the spirit of the Diagram, they were an act that bemused people through the years.”

The Bookseller’s features editor Tom Tivnan said that Stafford had actively campaigned for his win. “Mr Stafford’s Twitter electioneering for his book bordered on an Ahabian monomania. And why not?” said Tivnan. “I think writers have recognised that winning the Diagram could mean a boost in sale of tens, maybe even as much as a hundred copies. High stakes indeed. More likely, they are probably after the free bottle of plonk we give to the nominator.”

Stafford, who writes comedy and documentary for radio, said he had been fascinated with the trio for many years, particularly with Betty Knox, who went on to become a war reporter after she left the variety act, reporting from Normandy and the Nuremberg trials. “But there was very little out there about them,” he said.

So the author combed through newspaper libraries to find out what he could about the act, a Radio 4 documentary eventually putting him in contact with someone whose father had stood in when one of the trio fell ill during the 1930s.

“He had memories of them. One thing led to another and I made contact with three women who had been ‘Betty’ in the act, so gradually these people became real people to me,” said Stafford. “For me, it was a story I was passionate to tell. But when I touted it around agents, even the ones who were aware of the act thought it wasn’t a risk they wanted to take.”

He ended up at publisher Fantom Films, who he said were “small but enthusiastic”, and expressed the hope that winning the Diagram might mean he could “go into a bookshop and see it there”.

The Bookseller said that Too Naked for the Nazis’ win was the closest it had ever seen: the competition is decided by public vote, with Stafford’s title taking 24.8%, and Dr Jonathan Allan’s Reading from Behind: A Cultural History of the Anus 24.3%. Transvestite Vampire Biker Nuns from Outer Space: A Consideration of Cult Film was in third place, with Soviet Bus Stops fourth, and Reading the Liver: Papyrological Texts on Ancient Greek Extispicy in fifth place.

“When future historians write about 2016, they will inevitably look at two seismic events: the closest Diagram prize race of all time, and the election of President Trump which led to the downfall of western civilisation,” said the Bookseller’s diarist, Horace Bent.

“Until that dire time, we can celebrate a worthy winner from one of the strongest Diagram shortlists in recent memory. Too Naked for the Nazis is arguably the perfect Diagram winner, as if concocted by a team of crack Diagramologists – our voters’ penchant for nudity goes back to the very first winner, 1978’s Proceedings of the Second International Workshop on Nude Mice, while the Third Reich has been represented by titles such as How Green were the Nazis (2007). Mr Stafford has brought these two strands together in one irresistible package.”