A rep for the "Beauty and the Beast" star released a statement to CNN about the incident.
"Photos from a clothes fitting Emma had with a stylist a couple of years ago have been stolen," the statement said. "They are not nude photographs. Lawyers have been instructed and we are not commenting further."
In 2015, Watson discussed how she was threatened with the leak of personal photos after giving a gender equality speech as part of her duties as a UN Women Goodwill Ambassador.
Watson said she dismissed the threat and nothing came of it.
"I knew it was a hoax. I knew the pictures didn't exist, but I think a lot of people that were close to me knew gender equality was an issue but didn't think it was that urgent, that it was a thing of the past," Watson said at the time. "When they saw that the minute I stood up talking about women's rights I was immediately threatened, I think they were really shocked."