London, Nov 12 Britain's Got Talent star Susan Boyle has been given extra security after a crazed stalker turned up at her home.

Boyle, 48, had at first been bombarded by weird letters from the middle-aged American woman after she became famous, but the stalker later decided to visit her house in West Lothian, Scotland.

Luckily a bodyguard intercepted her, but the incident is said to have left Boyle "shaken up".

When Simon Cowell was informed, he instantly ordered more protection for her.

"Simon is not taking any chances," the Sun quoted a source as saying.

"This woman is constantly following Susan around the world. It is a middle-aged American woman who has become obsessed with her.

"At first, people thought it was no more than a nuisance. But after what happened to Leona everyone is taking extra precautions.

"This is an important month for Susan and everyone wants it to go smoothly," the source added. (ANI)