A TV producer has told how she was groped by a government official during a visit to 10 Downing Street.
Daisy Goodwin, creator of ITV's Victoria, said the man put his hand on her breast after they had met to discuss an idea for a new television show.
She told the Radio Times that the incident took place a few years ago when David Cameron was prime minister but she had never reported it.
A Number 10 spokesman said: "Allegations such as this are taken very seriously. The Cabinet Office would look into any formal complaint, should one be made."
Her story follows weeks of allegations of unwanted sexual advances in Westminster. Party leaders have agreed to set up a new independent complaints system amid concerns that reports of sexual assault and harassment are being ignored.
Goodwin said she had first met the official at a dinner and he had followed up with an email inviting her to Number 10.
She said the official, who was a few years younger than her, had shown her into an office before sitting next to her, putting his feet on her chair, and telling her she looked "like a Bond girl".
She wrote: "At the end of the meeting we both stood up and the official, to my astonishment, put his hand on my breast.
"I looked at the hand and then in my best Lady Bracknell voice said, 'Are you actually touching my breast?' He dropped his hand and laughed nervously."
Goodwin said it didn't occur to her to report the incident but had later reviewed her decision in the light of "abusive behaviour by men in power from Hollywood to Westminster".
"I think humiliating the official was probably the appropriate punishment, but suppose he tried it on with someone less able to defend themselves?" she said.