A second children's hospital has said it will refund donations from a charitable trust after allegations of sexual harassment at a fundraiser.
Two undercover Financial Times journalists reported that hostesses were groped and propositioned by guests at the Presidents Club annual fundraiser at London's Dorchester Hotel.
The event has raised £20 million for children's charities over more than 30 years, including Great Ormond Street Hospital (Gosh) and Evelina London Children's Hospital.
Both children's hospitals have said they will return all previous donations from the Presidents Club.
A spokeswoman for Gosh Children's Charity described the reports as shocking and said: "We would never knowingly accept donations raised in this way.
"Due to the wholly unacceptable nature of the event we are returning previous donations and will no longer accept gifts from the Presidents Club Charitable Trust."
Businessman Richard Caring, owner of London restaurants The Ivy and Scott's, successfully bid £400,000 to place his name on a new high dependency unit at the Evelina, the Financial Times reported.
A spokeswoman from the hospital said: "We are very alarmed by the allegations about the behaviour of some of those attending the Presidents Club fundraising dinner.
"This is not the kind of event we would wish to be associated with and we will therefore be declining funding from it and returning all previous donations from the Presidents Club."
Leading figures in business, politics and finance attended the event hosted by comedian and children's author David Walliams, who is not the subject of any allegations.
Businessman David Meller, who attended the fundraiser, is stepping down from the Department for Education board, minister Anne Milton told MPs.
Financial Times reporter Madison Marriage, who went undercover at the event, told BBC Newsnight: "I was groped several times and I know that there are numerous other hostesses who said the same thing had happened to them.
"It's hands up skirts, hands on bums but also hands on hips, hands on stomachs, arms going round your waist unexpectedly.
"The worst I was told by one of the hostesses was a man taking his penis out during the course of the dinner.
"The other one was another man telling a hostess to down her glass of champagne, rip off her knickers and dance on the table.
"I can't believe that it still goes on in 2018, I think it's quite shocking."
The Charity Commission said it is looking into the allegations "as a matter of urgency".
Tracy Howarth, head of regulatory compliance, said: "Charities have a duty to fundraise responsibly and in line with their values.
"Trustees must also consider the well-being and protection of staff and all those who come into contact with their charity - not just those they are there to help."
Hostesses were allegedly told to wear black underwear and "sexy" black shoes for their shift.
Items at the auction reportedly included lunch with Foreign Secretary Boris Johnson, a trip to the Windmill strip club in Soho and plastic surgery "to spice up your wife".
Organisers have vowed to investigate claims of "bad behaviour".
A spokesman said: "The organisers are appalled by the allegations of bad behaviour at the event asserted by the Financial Times reporters.
"Such behaviour is totally unacceptable. The allegations will be investigated fully and promptly and appropriate action taken."
The Dorchester Hotel said it is "deeply concerned" and an investigation has been launched.
"We were not aware of any claims during or immediately following the charitable event," a spokeswoman added.
Artista agency, which recruited the hostesses, told the Financial Times: "There is a code of conduct that we follow, I am not aware of any reports of sexual harassment and with the calibre of guest, I would be astonished."