Alexander Skarsgard has revealed childhood fame made him "paranoid."

The Swedish actor first appeared in Ake and His World aged just seven and by 13 he was starring in hit TV series The Dog That Smiled. However, he insists being a celebrity at such a young age is "f***ing weird."

Alexander - who quit acting for seven years in his teens - told Entertainment Weekly, "You have no idea what's going on, and who you are. There's nothing natural about being a celebrity."

Now aged 36, the actor is reliving his early career through 7-year-old Onata Aprile, his co-star in What Maisi Knew."When I was that age, it made me paranoid. I didn't like it all," he revealed. Alexander absolutely loved working with Onata because "she's so sensitive and real."

Currently unfazed by a future as a child star, her natural joyful personality has had a profound effect on Alexander. "That's what acting is, when you get so much from someone. She's a million times better than I am. She wasn't aware of the camera. She couldn't care less," he explained.

What Maisi Knew sees Onata in the title role in an adaptation of Henry James' novel of the same name. Alexander co-stars as Lincoln, Maisi's stepdad in a tale of parental disregard.