Children's author Philip Pullman had a walk-on part in His Dark Materials, a play based on his trilogy of novels, at the Oxford Playhouse Thursday evening. (Max Nash/Associated Press)

Bestselling British children's author Philip Pullman had a surprise walk-on role at the Oxford Playhouse Thursday night in His Dark Materials, a stage play based on his trilogy of fantasy novels.

Pullman, who lives in Oxford, England, was on stage for 10 minutes in the non-speaking role of an Oxford scholar in the opening night performance of the Birmingham Repertory Theatre production, adapted by Nicholas Wright.

He was invited to take part after attending the play's opening in Birmingham last month.

"When they asked me to take part, I realized I had a burning ambition to be on the stage," the 62-year-old author who studied at Oxford University, told BBC News after the performance.

"It was enormous fun," he added. "I really enjoyed the whole experience. Even though I didn't have a huge part, I was rehearsed within an inch of my life."

The audience was not told that Pullman would be in the production. The only clue they had to his identity was when his character was congratulated on his books.

Pullman's His Dark Materials trilogy is made up of The Golden Compass, The Subtle Knife and The Amber Spyglass. It follows the adventures of a young girl travelling through a realm of otherworldly creatures.

The Golden Compass was made into a blockbuster film in 2007, starring Nicole Kidman and Daniel Craig.

With files from The Associated Press