Scantily clad women are "unacceptable" at a betting industry conference, Britain's gambling regulator has said.
Sarah Harrison told the BBC that some women working at the ICE Totally Gaming event were wearing "little more than swimsuits", while men wore smart suits.
The chief executive of the Gambling Commission said the body could boycott future ICE Total Gaming events.
But the event's manager said the complaint was directed at a "very small" number of firms taking part.
Kate Chambers, managing director of ICE London, also said the show has been encouraging exhibitors to represent women more respectfully.
The three-day ICE Total Gaming event, held at London's ExCel centre, is an international showcase for the industry, attended by betting companies, technology providers, and casino operators.
The Guardian newspaper attended the event and spoke to some women working there.
One of them told the newspaper she was paid £100 a day to work on a stand. "'Somebody asked me yesterday how much I would charge', indicating that the request referred to sex," the newspaper reported.
Earlier, Ms Harrison told BBC's Radio 4's Today programme of her dismay at seeing a gender disparity at the show, with some women on exhibition stalls doing promotional work in revealing clothing.
"The men were wearing smart suits and women were being asked to wear not much more than swimsuits. That's totally unacceptable; it's not reflective of the modern economy," she said.
"This isn't about political correctness. It's about good regulation and good governance, because businesses that have a more diverse workforce are more likely to make better decisions. And that's critical from a regulator's point of view."