Tom Felton has had a middle-aged female fan following him around the world for nine years.
The 27-year-old actor - who played Draco Malfoy in the 'Harry Potter' film franchise - admits it is "strange" having such a keen supporter but he appreciates the woman is a massive fan of the movie series and is pleased she can get so much "joy" out of meeting the cast.
He said: "It's strange and if the genders were reversed, with a 50-year-old man supporting an 18-year-old girl, it would put up some warning signs.
"But for her, being a 'Harry Potter' fan and meeting the cast has given her a sense of purpose and joy - and that's not to be looked down on."
Tom admits his mother "worries" about him having such enthusiastic supporters but he has managed to turn it into a positive by making a new documentary, 'Tom Felton Meets the Superfans', in which he gets to know the female fan.
When asked when he first became aware of the follower, he said: "At a 'Harry Potter' premiere nine years ago.
"She came to mind when we did the programme. It was a chance to dig into her personal story and meet her.
"She's a sweet person, there's no malice behind it, but at the same time it's not something I fully understand and my mum still has her worries about people who talk to me as if they have known me for years."
But Tom was left feeling "uncomfortable" at one point during the show when he attempts to interview William Shatner.
He added to Metro newspaper: "I was at my most uncomfortable in that moment. It was cheeky of us to try to guerrilla-interview him but he saw me squirming and seemed to enjoy it."