Police are investigating a harassment complaint made by Canadian rocker Bryan Adams.
The 49-year-old reportedly became concerned after a mother and son, possibly from Romania, started turning up at his west London home after asking for his autograph in a restaurant.
The Evening Standard quoted a source saying: "Bryan likes to keep a low profile and is hardly the most recognisable rock star...
"He doesn't want them to get in any serious trouble, but he really wants to be left alone by them."
Adams, whose song Everything I Do (I Do It For You) remained at the top of the charts for 16 weeks, has had a panic alarm installed, according to the newspaper.
The singer's agent was not available for comment.
A spokeswoman for the Metropolitan Police said: "We are investigating an allegation of harassment made to the police on 25 November, by a man in his late 40s.
"There have been no arrests and inquiries continue."