Backstreet Boys star AJ McLean was turned off ever becoming a Scientologist after a strange visit to the Church's "megacentre" in Los Angeles.

The pop star took a tour of the place shortly after it opened because he was curious about the big building that had opened in his neighbourhood.

"I was living in Los Feliz, right down the street from the megacentre of Scientology, so I was curious," he said during an appearance on the Pretty Messed Up podcast. "I didn’t know what it was, I didn’t know anything about it. But I wanted to not go alone, so I took a friend with me.

"They brought us to this media room and they sat us down and they said, 'Would you mind watching this short film?' And we watched this short film - it was about 15 minutes long. Then I said, 'OK, well, that was interesting', and we went to leave and the door was locked. They wouldn’t let us out and they replayed the same film again... They played it three times until someone heard me knocking."

AJ didn't feel he and his pal were left in the locked room by accident, with him adding, "It seemed like a brainwashing technique."