Screenwriter accuses Harvey Weinstein of sexual harassment as she pitched movie idea

• Video report by ITV News Arts Editor Nina Nannar

A former actress and screenwriter has alleged that Hollywood producer Harvey Weinstein performed sex acts and begged her to watch him while she pitched movie ideas to him.

Louisette Geiss' allegations are the latest in a string of sexual offence claims against Weinstein.

Also on Tuesday, Hollywood A-listers Gwyneth Paltrow and Angelina Jolie both accused Weinstein of sexual harassment.

Paltrow said she was left "petrified" after Weinstein propositioned her when she was just 22, while Jolie vowed never to work with him again after a "bad experience" as a young actress.

Weinstein has denied many of the allegations and issued a vehement denial over three allegations of rape which emerged on Tuesday.

Speaking at a news conference with high-profile women's rights lawyer, Gloria Allred, Ms Geiss alleged the incident happened at the Sundance Film Festival in 2008.

She said that she spoke to Weinstein about an idea for a film she had at the festival and the pair then met in the restaurant of the hotel where they were both staying.

When the restaurant closed a short while later, Ms Geiss says Weinstein suggested they continue the meeting in office adjacent to his hotel room.

Ms Geiss continued that she was hesitant to agree to this due to "rumours" she had heard about the former film studio executive, but shook hands with him on the agreement that he "would not touch her" and he "laughed it off".

Ms Geiss also said a hotel security camera was above the pair when they shook hands.

She said the pair then continued their meeting in Weinstein's office, and after 30 minutes he excused himself.

Ms Geiss - who has appeared in Two and a Half Men - alleged that when Weinstein returned he was wearing nothing but an open dressing gown.

She continued that he told her to keep talking about her idea, but that he was going to get into a hot tub which was in an adjacent room.

Ms Geiss said that once she finished her pitch she was "nervous" and Weinstein asked her to watch while he performed a sex act.

She added that she told the film producer she was leaving but he "quickly got out of the tub and grabbed my forearm as I was trying to grab my purse.

"He led me to his bathroom, pleading with me to just watch him."

Ms Geiss told how she was "very scared" and tried to leave, claiming that as she did so Weinstein told her he could introduce her to "Bob Weinstein and that I could get a three-picture deal and he would green-light my script", but in order to get these things she had to watch him perform a sex act.

She continued that she was "on the verge of tears and quickly exited".

Now working in property, Ms Geiss said when asked about why she left the film industry she would tell the story she had just recounted.

Ms Geiss continued that she did not think she would "ever have a chance to stand up for myself against Harvey Weinstein" because if she "said anything he would have a ton of lawyers on my back and no one would trust me".

She also claimed that "sexual harassment has become commonplace in the entertainment industry" and said she knew many women who have stories of it.

The former actress, who became emotional during her speech, claimed that Weinstein is "breeding doubt about our stories and making light of it" and implored "other women to please stand up and come forward...

"Let us be the change we want to see in this world.

"Let's stop talking about making a change and actually make a change...

"Sexual harassment in the entertainment industry needs to stop and it needs to stop now."

Ms Allred explained due to laws in Utah, the state where the allegations are said to have taken place, the time frame in claims could be brought had expired.

However, she called on Weinstein and his accusers to set out their cases before a retired judge so that "justice" could be achieved.

The latest allegations come a day after Weinstein was fired from the Weinstein Company over allegations of sexual harassment that first appeared in the New York Times last week.

Several women have accused Weinstein of sexual harassment, and while he has not yet directly addressed the allegations, he did issue an apology to the women he had worked with days before his firing.

Also on Tuesday, Hollywood A-listers Gwyneth Paltrow and Angelina Jolie both accused Weinstein of sexual harassment.

Paltrow said she was left "petrified" after Weinstein propositioned her when she was just 22 while Jolie vowed never to work with him again after a "bad experience" as a young actress.

After he hired her as the lead in Emma, Paltrow claimed Weinstein summoned her to his suite at a Beverly Hills hotel where placed his hands on her and suggested they head to the bedroom for massages.

She told the New York Times: "I was a kid, I was signed up, I was petrified," adding she confided in her then-boyfriend Brad Pitt who confronted Weinstein which led to him threatening her not to tell anyone else.

"I thought he was going to fire me," Paltrow told the newspaper.

Pulp Fiction star Rosanna Arquette and French actress Judith Godreche made similar accusations according to the New York Times while Jolie said he made unwanted advances on her in a hotel room.

In an email statement to the publication, Jolie said: "I had a bad experience with Harvey Weinstein in my youth, and as a result, chose never to work with him again and warn others when they did.

"This behaviour towards women in any field, any country is unacceptable."

In an article in The New Yorker, also published on Tuesday, three women claimed that Weinstein had raped them.

Weinstein strongly denied the allegations in a statement to the magazine.

"Any allegations of non-consensual sex are unequivocally denied by Mr Weinstein," Sallie Hofmeister, a spokesperson for Weinstein said.

She continued: "Mr Weinstein has further confirmed that there were never any acts of retaliation against any women for refusing his advances.

"Mr Weinstein has begun counselling, has listened to the community and is pursuing a better path."

Actress Asia Argento and a former actress Lucia Evans went on the record to allege Weinstein forced himself on them sexually. A third woman spoke anonymously.

Former presidential candidate Hillary Clinton, who received major donations from Weinstein during her presidential campaign, said she was "shocked and appalled" by the revelations.

In a statement shared by her communications director Nick Merrill and retweeted by her, Ms Clinton said: "The behaviour described by women coming forward cannot be tolerated.

"Their courage and the support of others is critical in helping to stop this kind of behaviour."

Actors including George Clooney, Meryl Streep, Kate Winslet and Dame Judi Dench have thrown their support behind the women accusing him of sexual harassment while Ben Affleck said reading the rape allegations made him "sick".

Affleck said he was "saddened and angry that a man who I worked with used his position of power to intimidate, sexually harass and manipulate many women over decades."

He added: "The additional allegations of assault that I read this morning made me sick. This is completely unacceptable, and I find myself asking what I can do to make sure this doesn't happen to others.

"We need to do better at protecting our sisters, friends, co-workers and daughters. We must support those who come forward, condemn this type of behaviour when we see it and help ensure there are more women in positions of power."

Affleck launched his career through the success of 1997 film Good Will Hunting alongside Matt Damon which was produced and distributed through Weinstein's former company, Miramax, and which won the pair a screenwriting Oscar.