Disturbing scenes from the early life of Oliver Twist, Charles Dickens’s orphaned “item of mortality”, are among the most familiar in English literature. They have become the basis for popular films, television dramas and a much-loved musical.

But now a PhD student has identified a previously unknown source of inspiration for several of the most affecting elements in the novel, including the notorious underground world of Fagin, the seedy leader of a troop of young pickpockets.

Those passages, according to Eva-Charlotta Mebius, a Swedish student of literature at University College London, bear a strong resemblance to factual reports written by a crusading Scottish journalist 35 years Dickens’s senior: Robert Mudie. The two men shared a social cause: to shed light on the miserable lives of poor children in the city of London.

Mebius said the seeds of Oliver’s story were sown by a book that lay on Dickens’s shelf at the time of his death and had come out the year before his Twist was first serialised – Mudie’s London and Londoners of 1836.

“When I found the passages I was, of course, incredibly excited,” Mebius, originally from Stockholm, told the Observer. “I knew I would have to do a lot of work to connect Mudie with Dickens, but there were just so many similarities, both biographical and literary. The evidence for a connection just became stronger and stronger as I found out more and more about Mudie’s life and career in London.”

Experts, including Dickens’s biographer, Michael Slater, have been struck by Mebius’s discovery. “It would appear very strange indeed if Dickens was not familiar with this,” Slater told the Observer, adding he had never seen the connection between the writers made before.

The academic and Dickens scholar Professor Malcolm Andrews added that, while there is no firm proof, the similarities Mebius has spotted “between Dickens and Mudie in their detailed descriptions of London crime and poverty are very striking indeed, and it wouldn’t surprise me if evidence came to light that Dickens had indeed drawn on Mudie”.

Facebook Twitter Pinterest Charles Dickens published Oliver Twist as a book in 1839. Photograph: Bettmann Archive

Mebius, 30, lays out her argument in an essay for The Dickensian, the journal of The International Dickens Fellowship, edited by Andrews. In it, she describes finding proof that Dickens had once owned the book, and then highlights the key resonant passages of Mudie’s writing. The powerful moment when Dickens’s pompous character Mr Bumble, the parish beadle, leads tiny Oliver through the streets, like an object for sale, must surely have derived from Mudie, Mebius argues. In Mudie’s book a zealous official “Dogberry” figure, rather than a Bumble, “lays his giant gripe upon the child of six years old, and leads him through the village as ‘my prisoner’, flourishing his cudgel of office, and shouting his ‘Io triumphe!’ as he waddles, and most likely hiccups, along.”

The even better-known depiction of Fagin’s hidden den of young thieves, first printed in an episode of Oliver Twist in Bentley’s Miscellany, also seems to have its roots in Mudie’s journalism.

The Scotsman recounts the visit of a friend to a den, or “flash house”, down “unpaved” back lanes “covered with mud and mire”. It is a place, entered only by password, where thieves “revel in safety, and divide and occasionally sell their plunder”, and where youngsters are ruled with despotism by “a fence” who can report them to the police at any point.

Rather than Fagin, we meet a Captain J, who is “under middle age and middle stature, with features somewhat of the Israelitish cast, but prepossessing; and had he been met with in any other place, his manner, and the polite courtesy with which he received his guests, were calculated to inspire any confidence. He was genteelly dressed in black; his apartment was handsomely furnished; on the table there was a bottle of wine, with which he had been regaling himself; and the newspapers of the day, the Hue and Cry, and sundry hand-bills of ‘lost’ watches, pocket-books, and other articles, were beside him for intellectual edification.”

Mudie’s description is particularly persuasive for Andrews: “The access to the thieves’ London lair through a maze of streets, the password exchanged through a door hatch, the dark corridor, the arrival to find a room full of thieves, the gang-leader with a demeanour of wily courtesy, and so on; all these details (and more) in Mudie’s account are mirrored in Oliver’s experiences.”

Final confirmation of the likelihood of the source material for Twist came for Mebius when she checked the lists of the contents of Dickens’s libraries.

“I was absolutely thrilled when I finally found the 1836 edition of Mudie’s work in Stonehouse’s Catalogue of the Library of Charles Dickens from Gads Hill,” she said this weekend. “It was not listed under Mudie’s name, so I had to go over it a couple of times before I finally found it.” Her hope now is to find Dickens’s own copy of the book, sold in 1870.