Whodunnit? Did Agatha Christie ‘borrow’ the plot for acclaimed novel?

From The Guardian:

The striking plot of one of Agatha Christie’s best-known mysteries, The Murder of Roger Ackroyd, surprises each new generation of readers. But now there is a further twist in the tale. Fresh evidence suggests Christie may have taken the idea from an acclaimed Norwegian author.

Lucy Moffatt, a British translator living in Norway, has found a likely source for the famous solution to the murder in an early English magazine translation of Stein Riverton’s story Jernvognen (The Iron Chariot).  “You do have to wonder if her book was at least influenced by Riverton’s mystery,” said Moffatt.

Christie’s book, published in 1926, swiftly established itself as a classic of the genre. And in the 94 years since, her fans and publishers have been careful to guard the identity of the killer.

For Moffatt, a Christie fan, the power of Riverton’s book lies in its sinister handling of the environment, which mirrors the killer’s disturbed state of mind. “It is more of a study of madness,” she said, “It uses the landscape as metaphor, while Christie sticks to a smaller canvas.”