Sharon Osbourne has denied undergoing a cosmetic procedure to get a "designer vagina".

The former reality star told Howard Stern on Sirius XM radio that she had fabricated the story about getting vaginal rejuvenation surgery to "feel tighter" and admitted that misleading fans in an interview on The Graham Norton Show was flippant and stupid.

"He said to me 'what cosmetic surgery have you had?'" she told the radio host. "I said, 'Oh I've had my vagina tightened'. A flippant stupid thing to be silly."

A sceptical Stern pressed the 61-year-old Talk co-host for more information: "But it was true? I feel like you did [get the surgery] and now you're embarrassed to say it," he said.

"I swear on my children's lives I made it up - just to be flippant," the wife of Black Sabbath rocker Ozzy Osbourne insisted.

"How could I do that after I've had so much ill health?" she continued. She battled colon cancer in 2002 and had a preventative double mastectomy in November 2012.

"Now I'm going to start putting scaffolding up my vagina?" she quipped.

Osbourne had discussed with Norton going under the knife many times and claimed that no procedure was more painful than having her vagina tightened." Oh, it was just excruciating," she said.

Vaginal rejuvenation surgery, also known as a labiaplasty, is a procedure used to reduce the size of the labia.

Although it is usually offered as a treatment for women with physical discomfort, many women desire the operation because of concerns about the appearance of their genitalia.