Models Natalie Pack, Kara Del Toro, GUESS Foundation president Paul Marciano, models Olga Caro and Kristina Schlesinger attend the GUESS Foundation and Peace Over Violence Denim Day Cocktail Event at at MOCA Grand Avenue on March 22, 2016 in Los Angeles, California.
Marciano co-founded Guess in 1981 and has been its executive chairman and chief creative officer since 2015.
Guess, based in Los Angeles, says that Marciano will not be paid while he steps aside.
The cofounder of Guess has agreed to temporarily step down from his role amid allegations of sexual misconduct that are now being investigated by the company.
Marciano has repeatedly denied all of Upton's allegations in multiple statements, calling her claims "absolutely false" and "preposterous".
"I have pledged my full cooperation to the company, and I have the utmost confidence in our CEO, Victor Herrero, to continue leading the Company during this time", Marciano said in the press release.
Upton and Guess cut ties in 2011 after further reported instances of harassment.
Neither Marciano nor Upton was immediately available for comment.
"I was terrified. All I could think was if he was able to get into my room, it would not be good", she said. "Despite doing everything I could physically do to avoid his touch throughout the meeting, he continued to touch me in a very dominating and aggressive way, grabbing my thighs, my arms to pull me closer, my shoulders to pull me closer, my neck, my breasts, and smelling me".
Meanwhile, Marciano was accused of sexual harassment earlier this month by another Guess model who took her case to the LAPD.