Author and columnist Chloe Combi has said she had heard rumours that there were "real concerns" about David Walliams's behaviour within the publishing industry more than a decade ago.
Combi told BBC News she had heard there were allegations about his "behaviour around young female staff" and says she was told in 2015 to warn schools that he was "not an appropriate booking".
An investigation by the Guardian and ITV News alleged that Walliams has been accused by several women of sexual misconduct, inappropriate behaviour and abusing his position, which he denies.
HarperCollins, which published Walliams's best-selling children's books, have been asked for comment on Combi's claims.
In response to the Guardian and ITN report, a spokesperson for HarperCollins said the company had decided not to publish any new titles by Walliams and that it took "employee wellbeing extremely seriously".
Walliams told ITV News and the Guardian that he was "not a sexual predator" and had not "broken the law".
Combi said she was getting invited to events such as book launches around the time one of her own books was being published, and was also running a scheme to bring "high-profile and inspiring writers and speakers" to talk in schools.
At an event in 2015, Combi said she got speaking to someone "quite senior" in publishing, who warned her about Walliams.
"We were talking about [the scheme] and possible writers who might be good for the project to work well with teenagers," Combi said.
"She gave me some great recommendations and said to me: 'Whatever you do, don't invite David Walliams, and FYI if you are speaking to head teachers or teachers, please inform them that he's not a good booking, not an appropriate booking for a school'."
Combi continued: "I obviously asked why, and to be honest I had already heard quite a lot of rumours because those worlds are quite small and contained.
"One of the things she said was that there had been real concerns about his behaviour around young female staff."
Asked whether concerns about his behaviour was an open secret, Combi replied: "Yes definitely... and I'd heard it from people who worked in publishing, fellow writers, people kind of in celebrity and TV circles."
Combi said she never met Walliams herself, and said her information had come from "a number of people I was speaking to".
HarperCollins dropped Walliams last year and in September announced it would no longer be publishing his back catalogue.
The allegations against Walliams include:
In his statement to ITV News and the Guardian, Walliams said: "Looking back, I realise that at times I behaved thoughtlessly towards other people I had casual sexual relationships with.
"I realise I did not always take people's feelings properly into account. That is something I regret. And whilst a power imbalance is inevitable when one party is famous, abusing that power is something else entirely and it is something that I never did."
He added: "I am not a sexual predator. I have not broken the law, but I am devastated that some of the women I met 10 to 20 years ago have now expressed hurt or anger towards me."
Earlier on Wednesday, media minister Ian Murray said there is a "cultural problem" in the industry that needs to be "stamped out".
Giving evidence to the Digital, Culture, Media and Sport Committee, Murray said he was "deeply saddened and also angry" to see the prevalence of abuse by men in the media industry.
Meanwhile, Minister for Women and Equalities Bridget Phillipson paid tribute to the "bravery" of victims who have shared their experiences in recent days.
Speaking in the Commons, she said: "Women and girls should never have to shrink our lives or ambitions because of outdated, misogynistic attitudes, and the appalling testimonies we have heard in recent days underline how much further we have to go."
Comedian and podcaster Deborah Frances-White told BBC Radio 4's The World at One that young women are "definitely" still being exploited in the comedy industry.
She told the programme that perpetrators understand consent but they just enjoy the power that comes with ignoring it, adding: "The thrill is in the contravention of consent."
Asked whether she recognised the picture Russell Brand's conviction and allegations against Walliams had painted of the comedy industry, she said: "Yes, entirely."
She described an industry where she was asked to meet male producers in darkly lit rooms "walking a tightrope", having to make them feel attractive and avoid being assaulted as they influenced future employment opportunities.
She said these events are "definitely still going on" and that she is in a WhatsApp group with female comedians who share their experiences with each other.
Comedian Lucy Beaumont told Sky News that she was one of the people who spoke to the Guardian about allegations raised with her about Walliams.
Beaumont said she had been approached by a young TV worker who alleged inappropriate behaviour while working with Walliams on another show.
"This young person's job was to take young girls - he didn't think that they were children... he definitely knew that they were over 16 - he had to take them to Walliams's dressing room," she alleged.
Speaking to BBC Radio 4's Today programme on Wednesday, Labour MP Jess Phillips said the behaviour alleged "needs to be stopped".
"What is described in the David Walliams story is an absolute modus operandi, a target group of women of a certain age, the kind of women who don't have the same amount of power as if you were doing this to a 35-year-old woman who might have a bit more about herself in the world," she said.
