Gustav Martinez
J Walter Thomson's chief executive Gustav Martinez denies all the allegations made against him in the lawsuit J.Walter Thomson

One of the oldest and most respected global advertising agencies, J Walter Thompson, has come out in support of its chief executive following accusations filed in a federal court stating Gustavo Martinez had joked about raping female members of staff and had made racist comments in public. The lawsuit, filed by the agency's chief communications officer Erin Johnson, claims comments were made about "f*****g Jews" and to black people about "monkeys" by the agency's boss.

In a written statement released by the advertising agency's parent company WPP Group, Martinez strenuously denied all allegations and said: "I am aware of the allegations made against me by a J Walter Thompson employee in a suit filed in New York Federal Court. I want to assure our clients and my colleagues that there is absolutely no truth to these outlandish allegations, and I am confident this will be proven in court."

The complaint, filed on Thursday, 10 March, claimed that Martinez made it "impossible" for Johnson to do her job and that Martinez was apparently comfortable "making constant racist and sexist slurs, even on tape".

It also said that the J Walter Thompson boss often referred to Johnson as his "work wife" and once told a male colleague to leave his office because he and Johnson needed to talk about "the sex" according to the filing. It also claimed Martinez "grabbed Johnson by the throat or the back of the neck" while engaged in conversation on multiple occasions and at one point, in front of colleagues, Martinez asked Johnson to come over so he could "rape [her] in the bathroom".

The suit continued that Martinez had said multiple times that certain women should "shut up [their] mouths" and that he had said that a female executive he disliked needed to be "hogtied" and "raped into submission".

The suit also alleged that Martinez "regularly makes anti-Semitic remarks".

All allegations have been denied by Martinez and the WPP Group.