Marciano says, "Ms. Upton provided no details ... She leveled this malicious and false accusation only hours before a gala event at our headquarters in Los Angeles unveiling a new Guess campaign. Ms. Upton told TMZ that 'I'm excited to tell my whole story.'"
He goes on ... "I am told that she has been working with others for some time to defame me and will claim that I groped her among other things."
Marciano's response ... "This accusation is false. I have never touched Kate Upton. I have never been alone with Kate Upton. I have never acted inappropriately towards her."
Sources connected to Marciano tell us he believes Upton is lashing out because Guess ended its relationship with her after a disastrous photo shoot.