He told 'XL Semanal', the weekly magazine supplement of daily Spanish newspaper ABC, that at the age of seven he was diagnosed as having the language-based learning disability that can include problems in reading, spelling, writing and pronouncing words.

"I asked myself if I was normal or an idiot. I would try to concentrate but I felt anxiety, frustration, boredom. When I graduated from high school in 1980 I was functionally illiterate," he said.

"Nobody gave me a solution and I wanted to know why the system had failed. Finally, as an adult I learned to read perfectly through the method of (Scientology's late founder) L Ron Hubbard," the 46-year-old added.

The Church of Scientology, founded in 1954 in the United States by Hubbard, a science-fiction writer, teaches that technology can expand the mind and help solve problems.

Cruise's advocacy of Scientology, which has some 10 million members around the world, has sometimes landed him in hot water in the past.

German authorities were initially reluctant to allow the makers of Cruise's latest movie ‘Valkyrie’ about a plot to kill Adolf Hitler at German military sites because the actor is a Scientologist.