Katie Price said she felt "physically sick" and concerned for the safety of her children after a tracking device was found under her pink Range Rover.
A mechanic found the concealed GPS under her car while it was at a London garage for a routine check earlier this week, according to reports.
Price, 33, told The Sun: "I felt physically sick when I spoke to my mum and she told me how a mechanic had found a device hidden on the undercarriage of the Range Rover."
She continued: "It was found on Tuesday morning as I was working on publicity for my new book.
"The first thing I thought about was my kids and their safety. I needed to be with them.
"The garage had my car on a ramp and spotted this tracker. The car was last serviced on August 16, so I know someone's been following me or snooping around my property and shoved it on between then and now."
Price has three children - Princess Tiaamii and Junior with ex-husband Peter Andre and Harvey with former footballer Dwight Yorke.
The model, formerly known as Jordan, is currently promoting her 45th book and seventh novel, Santa Baby.
At the launch earlier this month she said she is "loving single love" after splitting from Argentinian model Leandro Penna.