A former hostess at the Presidents Club men-only dinner said the women were treated like escorts and "couldn't say no on the night".
The 26-year-old, who did not want to be named, said she saw guests "touching up" women young enough to be their daughters.
She worked at the event in 2016 and said most of the hostesses were aspiring dancers or actresses.
"When you walked into that ballroom you fully realised it wasn't a case of being a hostess - it was essentially escorting and it wasn't billed as that but that's essentially what it was," she added.
"You couldn't say no when you were there on the night, your time to say no had passed and you just had to get on with it, you had to do it.
"Your makeup, your hair, the dress everything had to be done right."
She continued: "I remember standing there being shocked at the age ranges of the men that were touching up these girls young enough to be their daughters.
"Most of the men there were late 40s or older and I remember looking at their hands and going 'oh wow you're all married'."
Hostesses were allegedly paid £130 to work from 4pm to midnight and extra if they agreed to stay until 3am.
"The girls working til 3am wore red belts with their dresses so the men knew they were more up for it," she said.
"They plied you with alcohol, they touched your waist, your bum, touched whatever they wanted really."
She said a number of the guests took women up to rooms in the hotel and had sex with them.
"I got on the bus home and calling my mum and saying I'm never going to do that again it was horrible," she added.
"I wanted to wash myself - and I didn't even do anything, nothing was even done to me, but it was the entire set-up.
"I know there were girls who were really drunk that then went up to the hotel rooms and did have sex with the attendees."
She said that some of the women worked the event every year but others had not been told what it would be like.
"These are very, very high worth individuals with a lot of power and unfortunately there's a lot of girls that were very naive, weren't making a lot of money or were potentially out of work," she added.
"We were all complicit in it but unfortunately that's one of the most well-paid jobs out of the year so people are going to do it.
"There's a lot of naivety with regards to that job but there were also a lot of girls who did it fully knowing and getting the most out of it."