While on holiday in Cape Verde in April with Kieran, her children and Jane, Katie caught the two of them kissing on the beach.
The 36-year-old told The Sun on Sunday: “The red mist came down and I marched over and grabbed Jane by her hair extensions.
READ: KATIE PRICE ADMITS KIERAN HAYLER AFFAIR WITH SECOND FRIEND CHRISSY TAYLOR
“I can’t remember everything because it was a blur, but I’m pretty sure I landed a punch on her face and knocked half of her front tooth out and left it wobbling. I hope so anyway.”
Katie admitted that her suspicions of her husband and her married best friend were high by the time they all arrived in Cape Verde.
She also claimed that Jane’s ‘transformation’ into a Katie clone was pretty much complete by the holiday and, saying: “I was more aware of Jane’s behavior and that she was looking more and more like me.”
GALLERY: FROM ABUSIVE RELATIONSHIPS TO HAPPY MARRIAGES - KATIE PRICE'S LOVE LIFE IN PICTURES
As her suspicions grew, Katie couldn’t shake the feeling Kieran and Jane were up to no good and followed them to the beach on night.
Katie continued: “I stood perfectly still for 30 seconds watching my best friend kissing my husband. I felt physically sick. Jane tried to tell me it wasn’t what it seemed.
“I went back to the villa shaking and called Kieran’s mum and Derrick who was still in the UK. Then Jane and Kieran came back to the villa saying ‘we were only cuddling’. Kieran looked proper scared. Jane didn’t say sorry then and hasn’t said sorry to this day.”
Jane’s husband Derrick flew to the holiday resort a few days later for a showdown. Katie told Jane to tell her husband what had happened but shockingly wasn’t bothered.
GALLERY: FROM PAGE 3 TO BOYFRIENDS, BOOBS AND BABIES - KATIE PRICE'S LIFE IN PICTURES
Katie said: [Jane] didn’t seem to care about anything except Kieran and just said ‘Does Kieran still fancy me?’”
The former glamour model told the newspaper that Kieran had convinced Jane he would leave Katie, marry and have children with her.
But Katie sensationally revealed today that Kieran was sleeping with another of her best friends at the same time as Jane.