TMZ has obtained a letter from Cohen's lawyer in which the hostess and former reality star denies ever having been intimate with Jay. She admits to having met him on more than one occasion, but only in a professional capacity.
Cohen's lawyer dismisses the allegations against his client as a "foul and phony mistress-rumor."
Cohen - who previously appeared on the Bravo reality series Princesses: Long Island - is currently a hostess at 1Oak, an NYC hot spot frequented by Jay, Beyonce, and other A-list VIPs.
Her lawyer's letter demands that Bauer Media Group - the corporation that owns In Touch, as well as several other publications that reported the affair - issue a full public apology to Cohen, Jay Z, and Beyonce.
The letter also requests that all references to the alleged affair be removed from websites operated by Bauer.
Jay Z and Beyonce have been plagued by cheating rumors in recent weeks, with tabloids linking Jay to a variety of women and claiming that Beyonce cheated with Julius De Boer, her longtime bodyguard.