Guests and staff at a controversial Presidents Club fundraiser allegedly rife with sexual harassment have been asked to provide evidence to the charities watchdog.
The Charity Commission issued a call for information about the men-only dinner at The Dorchester hotel on January 18, which gained notoriety following claims female hostesses had been groped.
It is examining whether trustees of the Presidents Club Charitable Trust had "complied with their legal duties and responsibilities".
An undercover investigation by the Financial Times lifted the lid on the exclusive event, alleging female staff were subject to sexual harassment and inappropriate advances by guests.
The report sparked a furious backlash and several high-profile charities refused to take any donations from the trust.
The Presidents Club decided to wind up its work in the wake of the scandal, but has assured the commission it will not disband until the investigation is complete.
In a statement released on Friday, the Charity Commission asked for relevant information but stressed criminal allegations should be referred to the police.
Head of regulatory compliance Tracy Howarth said: "It is important that anyone who attended or worked at the event knows they can come forward and raise concerns with us.
"We can't provide any legal remedy or compensation to individuals.
"But what we can and must do is to assess whether the trustees of the charity complied with important legal duties and responsibilities in managing their charity.
"We want to ensure we have all the information possible to make a balanced and reasoned assessment of the facts.
"So I would like to encourage anyone with relevant information to come forward."
Anyone with information is encouraged to contact the commission at firstname.lastname@example.org.