From the Guardian
Money in the Morgue is a particular kind of crime novel: a traditional golden age-style crime novel that also falls into the subgenre of “continuation novel”, written by Stella Duffy and featuring Ngaio Marsh’s beloved detective, Inspector Roderick Alleyn of the Metropolitan Police.
By continuation, they mean it was started by Ms. Marsh and completed, many years later, by Stella Duffy. Interesting!