The woman who claimed former Cabinet minister Damian Green acted inappropriately towards her has alleged that Downing Street was aware of his "pattern of behaviour."
Kate Maltby, who is three decades younger than Green, claimed he "fleetingly" touched her knee during a meeting in a pub in 2015.
She also claims a year later he sent her a "suggestive" text message after she was pictured wearing a corset in a newspaper.
The allegations, which Green says he does not recognise, triggered a Cabinet Office probe into his conduct.
It was this that led to Theresa May sacking her deputy after he made "misleading" statements about allegations that police found pornography on computers in his parliamentary office in 2008.
The Daily Telegraph reports that Maltby told a Downing Street aide about her claims against Green in September 2016, and she was informed it was part of a pattern of behaviour, and that "the Prime Minister knows."
Maltby told the newspaper: "I would never, never have told my story about Damian Green if I did not believe I was exposing a pattern of behaviour of which I thought the Prime Minister was personally aware."
Matlby told the BBC: "The reason that I didn't tell many people about the first encounter, the encounter which I felt the political mentorship, or even a job in the Conservative Party, was being offered at the same time as a sexual suggestion. The reason I didn't tell many people then, except my parents, is that I wondered if it was a one-off...and, eventually, I spoke to a very senior and long-serving aide of Theresa May."
Asked if she had said to the Cabinet Office investigation, headed by senior civil servant Sue Gray, that Downing Street was aware "there was an issue" with Green's behaviour towards women, Maltby said: "I gave evidence to the inquiry. As soon as I sat down with Sue Gray that, to the best of my knowledge, Downing Street was aware."
A Downing Street source said: "The Cabinet Office conducted a thorough investigation into a number of allegations about Damian Green. The inquiry findings were published yesterday.
"The PM has made it clear that everyone should be able to work in politics without fear or harassment - that is why she has brought forward a new Code of Conduct for the Conservative Party, and set up a cross-party working group to make recommendations about the Houses of Parliament."
Reporting the probe's findings, Cabinet Secretary Sir Jeremy Heywood said that with "competing and contradictory accounts of what were private meetings" it was "not possible to reach a definitive conclusion on the appropriateness of Green's behaviour with Kate Maltby in early 2015, though the investigation found Maltby's account to be plausible".
When Green left office on Wednesday he said he did not recognise Maltby's version of events, stating: "I deeply regret the distress caused to Kate Maltby following her article about me and the reaction to it.
"I do not recognise the events she described in her article, but I clearly made her feel uncomfortable and for this I apologise."