The writer bought a property in Scotland with the advance royalties from her first Potter novel in the late 1990s, but after the book propelled her to fame, a photograph of the property was published in a newspaper.
Rowling claims her full address could be seen in the shot - and she was forced to moved out because she feared being tracked down by "anyone who wanted to find me".
The Brit appeared at the Leveson Inquiry into press standards in London on Thursday (24Nov11) and told how she has battled to keep her family life private for more than 14 years.
She told the hearing, "That was the first house I had ever owned, and I bought that with the advances that I had received for the first Harry Potter book. We moved into that house in 1997 and we left that house in 1999. So during those two years it had really become untenable to remain in that house.
"Photographs had been published that showed not only the number of the house but also the name of the street. So I really was a sitting duck for anyone who wanted to find me."
Rowling also alleged a journalist once tried to contact her by slipping a letter into her five-year-old daughter's school bag.
She adds, "I can only say I felt such a sense of invasion... how angry I felt that my five-year-old daughter's school was no longer a place of complete security from journalists... It's difficult to explain - to people who haven't experienced it - what it feels like. The twist in the stomach - what do they want? It feels threatening to have people watching you."
Rowling is the latest in a string of celebrities to give evidence at the hearing, which was set up after the News of the World phone-hacking scandal exploded earlier this year (11).