Giant of American letters John Steinbeck beat the British authors Robert Graves and Lawrence Durrell to win the Nobel prize for literature in 1962, according to newly opened archives in Sweden – but he was not a popular choice.

The Swedish Academy keeps secret for 50 years all information about the authors nominated for the Nobel, only releasing their shortlist for the 1962 prize yesterday. The names of 66 authors were put forward for the prize that year, with the shortlist consisting of Steinbeck, Graves, Durrell, French dramatist Jean Anouilh and Danish author Karen Blixen.

Although Steinbeck was praised by the committee "for his realistic and imaginative writings, combining as they do sympathetic humour and keen social perception" when his win was announced, the newly declassified documents show he was actually chosen as the best of a bad lot.

"There aren't any obvious candidates for the Nobel prize and the prize committee is in an unenviable situation," wrote committee member Henry Olsson, according to a piece today by Swedish journalist Kaj Schueler in Svenska Dagbladet. Graves was rejected, reveals Schueler, because even though he had written several historical novels, he was still primarily seen as a poet. Olsson was reluctant to award any Anglo-Saxon poet the prize before the death of Ezra Pound, believing that other writers did not match up to his mastery; he further dismissed Pound in response to his political stance.

Blixen, author of Out of Africa, rendered herself ineligible by dying that September, and it was decided that "Durrell was not to be given preference this year" – probably, Schueler told the Guardian, because "they did not think that The Alexandria Quartet was enough, so they decided to keep him under observation for the future". Also a candidate in 1961, Durrell had in the previous year been ruled out because he "gives a dubious aftertaste … because of [his] monomaniacal preoccupation with erotic complications".

It is not clear why Anouilh was passed over, but the French poet Saint-John Perse had taken the Nobel in 1960, meaning that France was well represented on the roster of winners, and Svenska Dagbladet reveals that Jean-Paul Sartre, who would win the prize in 1964, was starting to be seriously considered as a candidate.

Steinbeck, therefore, remained. Previously nominated eight times, it was widely felt that his best work was behind him; Of Mice and Men was published in 1937, The Red Pony in 1945, The Grapes of Wrath in 1939, The Pearl in 1947 and East of Eden in 1952. But the Academy's permanent secretary, Anders Österling, believed the release of his new novel The Winter of Our Discontent in 1961 showed that "after some signs of slowing down in recent years, [Steinbeck has] regained his position as a social truth-teller [and is an] authentic realist fully equal to his predecessors Sinclair Lewis and Ernest Hemingway", revealed Svenska Dagbladet.

"Between Graves and Steinbeck, I find the choice very difficult – Graves is the older, and at the same time less high profile, while Steinbeck's reputation is of course more popular," wrote Österling. "Since Steinbeck's candidacy nevertheless appears to me to have a larger chance of gathering unqualified support, I consider myself free to give it precedence."

The choice, however, was heavily criticised, and described as "one of the Academy's biggest mistakes" in one Swedish newspaper. The New York Times asked why the Nobel committee gave the award to an author whose "limited talent is, in his best books, watered down by tenth-rate philosophising", adding; "we think it interesting that the laurel was not awarded to a writer ... whose significance, influence and sheer body of work had already made a more profound impression on the literature of our age". Steinbeck himself, when asked if he deserved the Nobel, replied: "Frankly, no."

His win followed that of Yugoslavian writer Ivo Andrićin 1961, beating JRR Tolkien – ruled out because the Lord of the Rings "has not in any way measured up to storytelling of the highest quality".