Ninni Laaksonen told Finnish newspaper Ilta-Sanomat in an interview published Thursday that Trump grabbed her rear while she and three other contestants were being photographed before an appearance on "The Late Show with David Letterman."
“Trump stood right next to me and suddenly he squeezed my butt. He really grabbed my butt,” she told Ilta-Sanomat. "I don’t think anybody saw it but I flinched and thought: 'What is happening?'"
Laaksonen said that she also attended a number of parties with other pageant contestants and Trump's wife, Melania.
"Somebody told me there that Trump liked me because I looked like Melania when she was younger," she told the newspaper. "It left me disgusted."
Laaksonen is the twelfth woman to accuse Trump of groping or kissing her without her permission.
Trump has threatened to sue the women who have come forward with allegations against him, calling them "liars."