Katie Price claimed she was warned by police about a recent plot to kidnap her son Harvey, after an electronic tracking device was found attached to her car.
During an appearance on ITV's Loose Women, the reality TV star, 38, said her vehicle was being serviced when the tracker was discovered.
She revealed that police seized her car and foiled a plot to hold her disabled 14-year-old son for a "£1 million ransom".
Price claimed she was told by officers that thugs planned to stage a fake road accident and take him from her car.
The mother-of-five also said there have been two previous failed kidnap attempts involving her family.
She said: "I've been through the ordeal of kidnapping threats a few times before and it is terrifying.
"£1 million ransoms and stuff. Scotland Yard actually knocked at my door - they knew exactly what was going to happen.
"The last time it happened, they even slept outside my door. They knew the people were going to do it. They knew how they were going to get into the house."
She added that her children "had to be followed to school because these people were going to follow me, stop the car and take Harvey for a £1 million ransom".
Former glamour model Price said she takes steps to preserve her family's safety but she still has concerns about being targeted.
She said: "The thing is, if they're going to get you then they're going to get you.
"You can buy all the security you want. I've got panic buttons and everything like that. But if something did happen, by the time the police would be able to get to my house, they would have already got me."
Price's eldest son Harvey, whose father is retired footballer Dwight Yorke, is autistic, partially blind and has Prader-Willi syndrome.
The TV star's son Junior, 11, and daughter Princess, nine, are from her previous marriage to singer Peter Andre.
Price's husband Kieran Hayler is the father of her youngest children - two-year-old son Jett and daughter Bunny, one.