Film producer Valeria Richter, who has part of her left foot amputated, says she was stopped at the Cannes Film Festival for not wearing high heels.
She told BBC 5 live red carpet officials pointed at her shoes and said: "No, no, this won't work, you can't get in like this."
Ms Richter, who was eventually allowed in, spoke after Cannes was accused of turning away women in flat shoes.
The festival has denied heels are part of the official dress code.
A spokeswoman said ushers had been "reminded" of this, suggesting women in flat shoes would now be admitted.
However, numerous festival-goers have reported seeing women being turned away.
Among them was Asif Kapadia - whose Amy Winehouse documentary premiered in Cannes last weekend - who said his wife had been stopped on the red carpet but was "eventually let in".
Ms Richter told the BBC she "couldn't keep her balance" in heels, after having her big toe and part of her left foot amputated.
She was stopped four times on her way into the premiere of Gus Van Sant's Sea of Trees on Saturday.
"They pointed their finger at my shoe and then were waving their fingers at me," she said. "It was quite obvious it was my shoes that was an issue."
"Obviously, I could wave my foot at them," she said, "and that would make the situation a little awkward for them, because I had a visible explanation [for not wearing heels]".
Although Ms Richter was eventually granted entry, she said "many of my colleagues who can't wear heels were rejected and did not come in."
British star Emily Blunt, whose latest film Sicario debuted in Cannes on Tuesday, called the alleged ban on flat shoes "very disappointing".
"Everyone should wear flats to be honest," she said.
"We shouldn't be wearing high heels anyway. That's my point of view. I just prefer wearing Converse sneakers."
However, the star opted for heels at the red carpet premiere of her film, which also stars Josh Brolin and Benicio del Toro.
Festival director Thierry Fremaux has said "rumours" of a ban on heels were "unfounded".
Writing on Twitter, he said: "For the stairs, the regulations have not changed: 'Tuxedo, formal wear'. There is no mention of heels."
But the row is awkward for Cannes in a year when it was seeking to address sexism in cinema.
The festival opened with a female-directed film for the first time since 1987, and organisers have endorsed a series of "Women in Motion" talks by stars such as Isabella Rossellini and Salma Hayek.
Wendy Constance, a children's author who attended Cannes in the 1970s, tweeted the festival had a less than stellar reputation when it came to women's clothes.
"Back in 1971, when I started work I asked for [the] rule about women not wearing trousers to be changed. It was. Forty-four years later."
"It's ridiculous that women are still being expected to conform," she added.
"Some women like high heels, but a lot of us don't!"