Christine Falls by Benjamin Black This crime novel set in 1950s Ireland is actually written under a pseudonym by Irish writer John Banville, winner of the 2005 Man Booker Prize for The Sea.
"This surely marks the first time any author has followed up his Booker win with a whodunit written under a pen name," says the Seattle Times article where I read about this."
The Times article was pointed out by Fay at Historical/Present.