Angelina Jolie and Gwyneth Paltrow are the latest women to come forward. Both said the incidents happened early in their careers.
On Tuesday, Weinstein also denied allegations of rape made in The New Yorker magazine.
Weinstein was fired on Sunday from his own film studio. The Weinstein Company board said on Tuesday that they would help any criminal investigation.
"My heart breaks for all the women who have suffered tremendous pain because of these unforgivable actions," Georgina Chapman, 41, told People magazine.
Chapman and Weinstein, 65, have two children together.
Meanwhile, ex-President Barack Obama and his wife Michelle have joined the growing public condemnation.
In a statement, they said they were "disgusted by the recent reports about Harvey Weinstein" and added that they "celebrate the courage of women who have come forward".
Weinstein was a big donor to the Democratic party under Obama's leadership. The Obamas' eldest daughter Malia worked as an intern at The Weinstein Company in New York earlier this year.
Weinstein also donated to Hillary Clinton's 2016 presidential campaign. Mrs Clinton said she was "shocked and appalled" by the revelations.
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