Lady Heather Mills McCartney has been criticised by police for making a "disproportionate" number of 999 calls.
Heather Mills McCartney made four 999 calls in a 24-hour period
Ch Supt Kevin Moore said there was a danger of further complaints not being taken seriously by his officers.
Mr Moore said it was not his personal view that Lady McCartney was "wasting police time" but Sussex Police did get a high volume of calls from her.
Lady McCartney said: "I didn't waste police time - they encouraged me to use them when I was being harassed."
A spokesman for Lady McCartney said she was nervous after getting death threats and being followed at night.
Mr Moore said his colleagues had dealt with four emergency calls from Lady McCartney in one 24-hour period.
He said: "We do have to respond to a disproportionate high volume of calls from Heather Mills McCartney because of the situations she finds herself in, and this is regrettable as it takes officers away from other policing matters."
But he added: "I hope my officers treat each call as seriously as they would do for anyone else contacting the police.
"We are duty-bound to respond, but clearly people who make lots of calls to police run the risk of being treated as the boy who cried wolf."
The 38-year-old former model, who is divorcing ex-Beatle Paul McCartney, has complained of being followed by photographers near her home in Hove, East Sussex.
Her sister, Fiona Mills, has made an internet appeal for an end to what she called media harassment of Lady McCartney and her daughter Beatrice, because of concerns for their safety.
Lady McCartney said she called the police "probably six times in 10 months".
"If your family were having death threats and the police had informed you about them, then the police would be keeping an eye on what's going on," said Lady McCartney.
"I wasn't given any security for me and my daughter so it's rubbish, as most of the stories are."
Lady McCartney was speaking during her first animal welfare publicity campaign since her split from Sir Paul - against pig farming practices.
Asked about her divorce, she said told BBC News 24: "I'm not a publicity seeker... I haven't gone round promoting things to finance my own pockets."
She added that she would "never get over" her relationship breakdown and "would always love Paul".