Los Angeles, Feb 10 (IANS): Actor Michael Gambon, best known for portraying Albus Dumbledore in "Harry Potter" franchise, has announced his retirement from theatre acting. He says he can't remember lines anymore.

The 74-year-old told the Sunday Times Magazine that he takes a long time to learn scripts and he would forget them quickly, reports hollywoodreporter.com.

"It’s a horrible thing to admit but I can’t do it. It breaks my heart. It’s when the script’s in front of me and it takes forever to learn. It’s frightening,” he said.

Gambon said he had recently resorted to using ear pieces to feed him lines but then his forgetfulness had become so pronounced that he realised six months ago it was time to bring down the curtain on a five decade career in the theatre.

“There was a girl in the wings and I had a plug in my ear so she could read me the lines. And after about an hour I thought, this can’t work. You can’t be in theatre, free on stage shouting and screaming and running around, with someone reading you your lines,” he added.