NEW YORK, United States — Guess? Inc. Chairman Paul Marciano, accused of sexual harassment by Kate Upton this week in allegations that invoked the #MeToo movement, denied any misconduct toward the supermodel and actress.

In a regulatory filing on Thursday, Guess said that it became aware of Upton’s “concerns” on Wednesday when she posted the accusations on social media. Though Marciano disavowed wrongdoing, the company said it “will fully investigate her claims once they are known to determine if they have any merit.”

The Los Angeles-based company also said it has investigated two other allegations against Marciano that were brought forth by an entertainment website in November. One — taken from a lawsuit filed in 2009 — was denied by the executive at the time, Guess said. The company and outside counsel investigated and didn’t corroborate the plaintiff’s claims, according to the filing.

A different woman alleges that Marciano sexually assaulted her during a visit to Guess headquarters, according to the Blast entertainment site. The executive denies that allegation as well, Guess said.

“To date, the current investigation has not corroborated either allegation, and the board of directors has been unable to determine that either accusation has merit,” the company said in the filing.

Shares of the fashion house plummeted on Thursday after Upton’s allegations surfaced on Instagram and Twitter. The former Guess model said that Marciano “shouldn’t be allowed to use his power in the industry to sexually and emotionally harass women.” She added the #MeToo hashtag, which has become a rallying cry for the movement against sexual assault and workplace misconduct.

Marciano stepped down as chief executive officer of Guess in 2015, but he still has major influence over the company in his roles as chairman and chief creative officer. He art-directed the latest advertising campaign for Guess, featuring Jennifer Lopez, and appeared at a party celebrating its launch on Wednesday night.

“I’m disappointed that such an iconic women’s brand @Guess is still empowering Paul Marciano as their creative director,” Upton said in a tweet.

In the aftermath of Upton’s remarks, Guess suffered its worst stock decline in more than five years, sending the shares down 18 percent to $15.11. They had gained nearly 40 percent last year.

Marciano held more than 14 percent of Guess shares as of March 2017, according to data compiled by Bloomberg. That stake would be worth roughly $39 million less after Thursday’s decline.

Upton also spoke briefly with TMZ as she walked through Los Angeles International Airport on Wednesday night. “I’m excited to tell my whole story,” she said.

For now, Guess isn’t aware of specific allegations that Upton is making, the company said on Thursday.

By Kim Bhasin with assistance from Melodie Warner and Lindsey Rupp; Editor: Nick Turner.