• by Steve McClellan  @mp_mcclellan, March 15, 2016

WPP’s J. Walter Thompson has hired a top New York labor and employment attorney to head its internal investigation looking into charges that its CEO Gustavo Martinez sexually harassed a senior staffer at the firm and then retaliated against her when she complained. 

JWT’s own investigation into the matter began last week and was handed over to the outside counsel — Bettina Plevan with the law firm of Proskauer Rose earlier this week. 

Plevan will be looking into charges made by JWT Chief Communications Officer Erin Johnson that Martinez sexually harassed her on numerous occasions and then retaliated when she complained. She filed suit last week, also charging that Martinez regularly made racial and anti-Semitic slurs and frequently made inappropriate comments about sex and rape. 

WPP CEO Martin Sorrell told senior company executives about the hiring of Plevan in an update memo circulated Monday, according to sources familiar with the situation. In the memo, those sources said, Sorrell stated that JWT had “decided to retain an outside law firm to conduct an independent investigation into the allegations in the [Johnson] complaint. Bettina Plevan of Proskauer Rose LLP will lead this. Feel free to use this information with clients, our people and other parties as you see fit." 

Johnson filed an amended complaint Monday asking the U.S. District Court (Southern District) in New York to allow her to submit a DVD recording of a JWT company retreat in Miami last year that she argues supports some of her claims. 

While Plevan is now overseeing JWT’s internal investigation, sources said that WPP’s lead attorney in the U.S., Gilbert & Davis, is currently defending WPP, JWT and Martinez in the lawsuit filed by Johnson. A formal response to the suit isn’t due for several more weeks.