Susan Boyle is "on edge" after a crazed fan chased her and tried to break into her hotel room.

An obsessed admirer followed the Scottish singer up four flights of stairs as she tried to get into her suite at the Hope Street Hotel in Liverpool, North England, following her performance with the cast of her I Dreamed a Dream musical.

The man fled after the security team tried to detain him at the scene this week.

The scare comes just two weeks after Susan's former gardener turned up to her home in Blackburn, West Lothian, demanding money.

"She has been a little on edge, especially with what happened at her home recently, so everybody is on high alert," a source told Scottish newspaper the Daily Record.

The witness also described the latest incident as "creepy". The 51-year-old is now making sure she is chauffeured to and from the Liverpool Empire theatre.

"Some fans waited for her in the lift but Susan decided to take the stairs," the source said.

"Susan's room was on the fourth floor so it was a fair old walk. He realised she was taking the stairs so started following her.

"She managed to get in the room safe but he then made a dash for her door saying he wanted her autograph. It was really scary for Susan to follow someone up the stairs for four floors is creepy."

The singer has grown a large fan base since she shot to fame on Britain's Got Talent in 2009.

However, she has fallen victim to followers taking their admiration too far. In 2010, a man broke into the bedroom of her house after she returned from recording a charity single for victims of the Haiti earthquake. At the time she believed it was the same man who tried to break in the previous Christmas. The latest attack has left her "terrified and shaken," the source added.

"She absolutely loves performing but sometimes the reaction of fans is really intense."