A trove of never-before-seen letters reveal that French literary giant Marcel Proust made a previously unknown trip to England and was driven around the bend by a scrounging house guest.

Any crumbs about the author (1871-1922), whose monumental In Search of Lost Time is considered one of the greatest books of all time, are treated with fan-boy excitement by the world's many Proust obsessives. 

So a new book of letters between the writer and a lifelong banker friend, published in France on Thursday, makes for a veritable banquet of Proustian marginalia.

Horace Finaly was a classmate who ended up heading the Banque de Paris et des Pays-Bas, today's giant BNP Paribas. 

The letters had been kept by Finaly's family and emerged last year when they were sold at auction for 78,000 euros. 

Among the nuggets is that Proust needed Finaly's help to get rid of a free-loading house guest who had been staying with him for nearly three years, racking up vast tailoring bills in his name. 

Proust had taken in Swiss emigre Henri Rochat in 1918 when he was working as a waiter, thinking it would only last a few weeks. 

A first-edition of the multi-volume 'In Search of Lost Time'. Photo: Joseph Agius

But Rochat “spent a lot more than Proust himself”, Thierry Laget, who edited the letters, told AFP. 

Rochat may have helped inspire one of the central female characters of In Search of Lost Time” – Albertine, who enjoys luxury clothes and other lavish gifts. 

“He was a dandy, who offered nothing other than this inspiration, a few games of cards and some nights at the piano,” Laget said. 

Trip to England

Ultimately, the two friends hatched a plot to get rid of him, with Finaly finding Rochat a job in a bank in Recife, Brazil. 

Worried that Rochat will back out, Proust writes that he had left an allowance for him with the captain of the ship – only to be handed over once they had set sail. 

Little else is known about Rochat, who is thought to have died in northeastern Brazil around 1923. 

Another scoop in the letters is a very brief trip to England – the only time Proust is thought to have crossed the Channel despite his love of English literature and his many admirers there. 

Proust mentions travelling from Ostend to Dover with Finaly at a young age –though they came straight back.

“Do you remember, we took the boat together to Dover and without even getting off, took the next boat and returned with just a little seasickness,” the letter reveals. 

One of the first-edition volumes. Photo: Joseph Agius

“It's nonetheless the only thing that allows me to say to my English readers that I was once 'in England', if I ever responded to their letters.”

Such details will keep Proust scholars busy for years. 

The letters were bought at auction by the Societe des Hotels Litteraires, which runs a series of hotels dedicated to great writers. 

“I was not expecting the letters at all,” said Laget. “When they were shown to me, I was amazed.”