A former Playboy centerfold model has sued a prominent Republican fundraiser, her former lawyer and the lawyer for former adult-film star Stephanie Clifford in connection with the breakdown of a $1.6 million hush-money agreement, according to court documents filed Friday.

At issue in the lawsuit filed under seal by Shera Bechard in Los Angeles County Superior Court against Elliott Broidy, a Los Angeles-based GOP fundraiser and venture capitalist, is their agreement from late last year to not disclose their affair. The Wall...