Music mogul Simon Cowell has vowed to step up his security after a bugging device was reportedly found under his car.
The 'X Factor' judge became suspicious his movements were being monitored after repeatedly spotting a mysterious biker at supposedly private meetings.
And his fears were confirmed when a security sweep uncovered a hi-tech tracking device attached to the undercarriage of his Bentley Continental.
A shocked Cowell is now considering calling in cops and increasing his protection.
A source told the Daily Mirror: "Simon is completely freaked out by this. He can't believe someone has gone to so much trouble and expense to monitor his every movement. It's extremely sinister.
"He was aware that someone, dressed in motorbike leathers and a crash helmet, kept turning up a few minutes after he went everywhere. He couldn't work out how that person knew his movements.
"His security team found this tracking device under the car... Simon has his suspicions as to who is responsible. He is so angry he is considering calling in the police to investigate further."