Zelda Perkins told the Financial Times she signed a non-disclosure agreement in 1998 after making the accusations.
She said he asked her to give him massages and tried to pull her into bed, but she "was made to feel ashamed for disclosing his behaviour".
Weinstein has denied any allegations of non-consensual sex "unequivocally".
The former assistant said she reported her allegations after a female colleague told her she had also been sexually harassed by the film producer.
The two women subsequently sought damages and were awarded a sum of £250,000 ($330,500), split equally, but also signed a non-disclosure agreement, prohibiting them from discussing the allegations.
By breaking the agreement, Ms Perkins could be liable to repay the settlement, and potentially pay damages and other legal fees stipulated in the contract.