Leah Remini is ''very excited'' about her upcoming tell-all book about Scientology.

'The Talk' co-host has unveiled the title and cover for her upcoming book, which will lift the lid on her time as part of the controversial religion, which she quit in 2013.

Leah, 45, unveiled the cover for 'Troublemaker: Surviving Hollywood and Scientology' on Twitter this week, writing: ''Very excited about this... #TroubleMaker (sic)''

The actress' upcoming book has been praised by fellow ex-Scientologist, film director Paul Haggis.

He tweeted: ''Bravery is a rare commodity in Hollywood. In @LeahRemini 's case you have to weigh it by the ton.''

The former 'King of Queens' star quit Scientology in July 2013 and later admitted to Ellen DeGeneres she had lost friends because of the religion's disconnection policy, which means current members cannot have contact with former members.

She said: ''My mother got involved when we were very young, so it's all we ever really knew. But over time, my eyes opened and I could no longer be affiliated with the organisation and my family felt the same, so we left.''

She added: ''It's hard. We lost friends that can no longer talk to us who are still in the organisation.

''And these are friends that we've had for dozens of years. But I have great friends, other friends that are not in the church, that have stood by us. Our family is stronger, we're together and that's all I can ask for.''