The family of Susan Boyle say they fear for her safety after a break-in at her home.
The Britain's Got Talent star has insisted the incident is "nothing to worry about", but her brother said he was worried she is not properly protected.
The singer, 48, disturbed an intruder as she returned to her home in Bathgate, West Lothian on Tuesday, after recording the Helping Haiti charity single in London.
Boyle's brother John said he was very upset about the "lack of security".
Mr Boyle, 59, told The Sun: "Her management company are too busy counting the money Susan has made them to consider her safety.
"The family have told them several times that vast improvements need to be made to avoid something like this happening.
"Susan is a massive world star and needs better protection.
"You look at what happened to John Lennon in New York - it's really worrying."
The former Beatle was shot outside his apartment by Mark Chapman, who had asked the musician for his autograph only hours before.
Police said a 16-year-old boy was questioned in connection with the break-in at Boyle's house but was released without charge.
Detective Constable Brian Thompson, of Lothian and Borders police, said: "Given her high profile, we can't rule out that this is something concerned with her fame. But alternatively an opportunistic thief could be a possibility as well."
Meanwhile Boyle's musical idol Elaine Paige has described the singer as like a "virus" and cast doubt on her hopes of an enduring career.
Paige, who duetted with Boyle for a TV special, said: "It's all about turning someone into an immediate celebrity at the expense of longevity and working hard and experience.
"Susan Boyle is doing terribly well considering she literally came to the attention of the world overnight with the advent of YouTube.
"She was like a virus really that spread across the world in a nanosecond."
Asked if she thought Boyle's success would last, Paige told the Daily Mail: "That's a good question. She is a major star because of YouTube.
"Longevity is gained through knowledge, experience and effort so it will remain to be seen."
/Sky News/