Sam, who plays Ronnie Mitchell in the soap, has also been forced to call the police, after being left terrified over the ordeal.
According to reports, the obsessed fan, who sent love letters to Sam, was spotted waiting outside her house – which she shares with husband Mark and their two young children.
Speaking to The Sun, an insider said: “This stalker has become completely obsessed with her and has been sleeping outside her house so that he can spy on her.
“The family are terrified that he will try to get into the grounds of the property or even the house. Sam has also received a weird love letter from this oddball that really disturbed her.”
EastEnders bosses are taking Sam’s concerns seriously and have told security to be aware of anybody suspicious hanging around the set, which is located in Elstree.
A police spokesperson confirmed: “A report was made on Thursday relating to indigents of suspected stalking at a property.
“An investigation has been launched an enquiries are ongoing.”
It’s been alleged that Mark, 54, has also been subjected to threats. The source added: “Everything became too much and on Thursday they decided to call in the police. Hopefully they will catch them soon and this can be brought to en end once and for all.”