Thanks to Richard Pearson for pointing out a Times Literary Supplement article on Dickens meeting Dostoevsky. We talked about that meeting a good while back. It appears this story of a meeting of great authors has been repeated by reputable news outlets a few times, while the scholars who should know all there is to know about it say it never happened.
Eric Naiman writes, “The newspaper’s collective unconscious was unable to give the story up. It demands retelling, and by now Dickens and Dostoevsky can be found meeting all over the web. Their conversation appeals to our fancy while, as Gates realized, comforting us with a reaffirmation of what we already know.”

Tomalin regarded publication of the article in the Dickensian as an authentication of the encounter; moreover, the meeting had subsequently been mentioned in monographs by two leading Dickens scholars, Malcolm Andrews and Michael Slater. “We were all caught out”, Tomalin wrote. “The hoax was a clever one precisely because it convinced so many Dickens scholars.”
This is odd, backwards logic. The hoax wasn’t clever because it convinced so many Dickens scholars; rather, it was clever for the same reason it convinced them: because it was modest.

Apparently, Michael Slater’s biography brought this encounter to the attention of book reviewers, which raised it’s profile among scholars of Dostoevsky. Then, the koshka was out of the sumka.
But there’s more. If you read Naiman’s lengthy investigation, you will discover that the name of the writer who foisted this mythical story on us is but one pseudonym of many for an independent scholar who could never get hired to a British university. The story of how Naiman tracked him down is incredible and vulgar, but if you want a literary mystery, read this one.