Zelda Perkins, a former assistant to Harvey Weinstein, has begun to give evidence to MPs on the Commons Women and Equalities Committee.
In the first oral evidence session on sexual harassment in the workplace and the use of non-disclosure agreements, Ms Perkins told MPs she left his company Miramax after Weinstein "sexually assaulted and attempted to rape a colleague of mine, who had recently been employed and had only met him once".
She told the committee: "When somebody comes to you and says that has happened there is not much choice about what you should do."
Ms Perkins told MPs she was advised by lawyers that the women would be "utterly crushed" if they attempted to take legal action.
Describing the non-disclosure agreement she signed, she said it was a "morally lacking agreement on every level", adding there were clauses that precluded her from speaking to colleagues, friends and family about what happened but also obligated her to get medical practitioners and lawyers to sign agreements before she could speak to them about what had happened.
She told MPs: "We were still under pressure to not name anybody."
Ms Perkins said her former colleague, who was the victim of the alleged assault, sought counselling but never spoke about the incident because "she was so afraid of this agreement she felt she was not allowed to".
Ms Perkins said that in the process of reaching a settlement agreement when she left Miramax she spent three days in the offices of the company's lawyers.
Recalling a 12-hour session that went on until 5am, she said: "It was a reasonable environment up to a certain point but what was unreasonable about it was the pressure we were put under collectively.
"I felt my lawyer was put under a huge amount of pressure, with me and apart from me."
Ms Perkins told MPs she was asked to name every single person she had told about the process and why she was leaving, adding they lost some of the obligation they wanted from the agreement so that she did not have to name people.
Describing the session, she said: "It was a siege mentality, you lose track of time and place, you're in a battle."
She was asked by Labour's Jess Phillips: "Did you feel there was a parity in the level of legal resources and expertise available to you, was there equality of arms?"
Ms Perkins replied: "No, obviously not. I didn't know my rights and I didn't know where to go for advice or how to get advice. I went to the closest lawyer to my office."