The 31-year-old glamour girl had recently revealed she was raped when she was younger, but had not named her assaulter.
The Sun quoted Jordan as saying: "A famous celebrity raped me and Peter knows who it was."
"It was years ago, before I was with Pete, and my friends and family knew about it at the time."
Jordan has refused to comment any further on the issue but her revelation has kept her pals guessing.
A friend said: "We were stunned as it makes everyone feel really paranoid. Katie has always been a party animal and enjoyed wild nights out with loads of blokes."
"It's horrifying to think that someone attacked her in this way."
However, ex-hubby Andre claims to know nothing about Jordan's rape ordeal.
He said to a pal: "Once again, Katie is saying things that don't make sense to me."
"First she says she was raped, now she's upping the ante by claiming it was a celebrity. If she had been raped, why didn't she report it to the police? It's a very serious matter."
But Jordan insists he knows about it.
She said: "He's being really cruel. He knows exactly who did it."