A man in his late 20s followed the Dirty Picture star to her film sets and eventually reached her apartment as well, the Hindustan Times reports.
"He used to be there on her sets. He used to be there in her building. Once unknowingly, Vidya even nodded to him and said namaste," a friend of Balan explained.
A resident of the same apartment block said: "He was obsessed with Vidya.
"The stalker managed to go up to Vidya's flat. Thankfully, Vidya was not at home at that time. Her sister, who delivered twins in November last year, opened the door. When told that Vidya had gone out, the stalker asked if Vidya had gone out with her niece Ira and nephew Ruhaan."
The actress became suspicious and asked the security guards to keep a watch on the stalker.
When the stalker returned, the security guards called the police, who issued a warning to the man, before releasing him.
Katrina Kaif, Kangna Ranaut and Minissha Lamba have also previously been the victims of stalkers.