The alleged incident occurred in Liverpool after she had performed in musical I Dreamed A Dream at the Empire Theatre.
A source described to The Mirror how the incident occurred, saying: "Some fans waited for her in the lift but Susan spotted them and took the stairs.
"Her room was on the fourth floor so it was a fair walk. This man realised she was taking the stairs so he followed her. He made a dash for her door, saying he wanted her autograph, but she managed to get into the room safe and sound.
"It was really scary for her. To follow someone up the stairs for four floors is a bit creepy. She was terrified and shaken."
The source added: "The attention she was getting from fans was a bit much, especially given what happened at her home recently (her former gardener allegedly turning up at her house and drunkenly demanding money).
"The last thing she needed was someone trying to get into her room.
"Her nerves were already frayed and she shouldn't have to worry about people hounding her at her hotel."