U.S. Senate candidate Charles Boustany filed a defamation lawsuit Monday against the author and publisher of a book that claims the Republican congressman paid for prostitutes who were later murdered.

Boustany’s suit states “Murder in the Bayou” author Ethan Brown and publisher Simon & Schuster printed the book last month despite knowing its claims “were known to be false when made or were made with malicious intent and reckless disregard for the truth.” The Louisiana congressman said the allegations in the book are “despicable lies.”