Tom Felton has admitted he may be trying to exorcise his “inner demon” by playing dark characters.

The 27-year-old British actor found fame as Harry Potter’s wicked enemy Draco Malfoy, and next stars in new TV drama Murder In The First as an arrogant Silicon Valley technology billionaire who becomes the prime suspect.

Tom said: “I don’t know why [I always play these characters] – there must be some kind of inner demon trying to get out of me! I’m not a very sinister person in real life. I just really enjoy stepping out of my own shoes and going as far opposite as possible.”

“Erich is very un-laid-back. He doesn’t have any time for people who don’t see the world the way he does. He has very little patience. I consider myself quite a tolerant, patient person, and he’s the absolute opposite of that.”

Although Erich reveals himself as a cut-throat figure from the outset, a plot ridden with twists and turns will keep viewers guessing as to the true villain’s identity right to the series’ end. Steve Bochco, the Emmy-winning writer behind NYPD Blue, and newcomer Eric Lodal who co-wrote the series, were so secretive that even Tom was left in the dark.

He said: “Every episode, it looks like someone else is in the firing line. We had daily sessions in the hair and make-up chair trying to guess who it was. I was in complete turmoil – I had no idea whether my character was guilty or not!”

Murder In The First begins on Fox on Friday, January 16.