Erin Johnson, chief communications officer of WPP's J. Walter Thompson, has filed a bombshell lawsuit against the agency and CEO Gustavo Martinez, alleging the chief executive made crude jokes about raping employees and used racial and ethnic slurs.

Martinez, Johnson

Martinez, Johnson

Johnson alleges Martinez made apparent jokes about raping her and other female staff members. He also criticized Jewish and African-American people, according to the suit first reported by the New York Post.

Johnson, an 11-year staffer of JWT, alleges the company reduced her pay and job responsibilities after she complained to supervisors.

In a statement, Martinez said he wanted to "assure our clients and my colleagues that there is absolutely no truth to these outlandish allegations and I am confident that this will be proven in court."