Leah Remini has spoken about her dealings with the Church of Scientology and one of its best-known followers, Tom Cruise, in a tell-all television interview in the United States.

The King of Queens actress, who left the church two years ago, has spoken to 20/20 about her experience in the new-age religion in an interview that airs on Friday.

Remini, 45, told the program criticising Cruise was considered an "evil" act within Scientology circles.

"Being critical of Tom Cruise is being critical of Scientology itself," she said.