Susan Boyle doesn't think she can trust anybody.
The 'Wild Horses' singer has become a worldwide star following her performances on UK TV show 'Britain's Got Talent' last year, but she is now wary of letting people into her life in case they are just using her, according to her brother Gerry.
He said: "She's living her dream. The downside is that she has to be careful who she's involved with.
"I speak to Susan once in a blue moon. She says she's not sure who she can trust. We don't want anything from her, but we feel that the people around her are there for commercial reasons. We can't get near her. It's like a secret society.
"Our relationship's changed. Although her career is going from strength to strength, she's losing contact with some of her family."
Although he insists the 49-year-old star is happy in her life, he thinks Susan is worried her success may be taken away from her.
He told new! magazine: "She's happy, but I think she's living in fear that someone will take all this away.
"I've tried to give her advice but she won't listen. We are very protective of her. We don't want to spoil the party, but we can't sit here and not say anything."
Gerry also fears his sister is struggling to cope with the pressure put on her, which may explain some of her recent eccentric behaviour.
He said: She has good days and bad days. She's under intense pressure now. I don't think Susan realises just how famous she is.
"I don't think she's got learning difficulties. In my opinion, it's a personality problem. You and I would shrug off disappointment, but it's a major issue for her."