Miley Cyrus and Liam Hemsworth are officially ''on a break'' from their relationship.

Signs the twerking 'Wrecking Ball' hitmaker and her Australian actor fiancé were going through a bad patch were apparent at the weekend, when she unfollowed him on Twitter, and now friends have confirmed they are not together at present.

A source told ''They've split for now. Miley and Liam have a very tumultuous relationship and both are exhausted. It's a complicated relationship. The wedding is on hold, for now. It's not cancelled but it doesn't look promising.''

Another friend says Miley's new image and recent behaviour - which has included her gyrating against Robin Thicke at the MTV Video Music Awards (VMAs) in a latex bikini, and appearing naked and licking a hammer in her latest music video - is too much for 'The Hunger Games' star to handle.

The pal said: ''Liam really does care about Miley, but her racy new look and sort of ghetto attitude isn't exactly what he signed up for.

''Her VMAs performance absolutely mortified him and he couldn't be more embarrassed. He doesn't really see anything sexy about what she did on stage.''

Another friend added: ''Liam is a serious actor with a growing career, whereas Miley has just turned into a joke.''

Earlier this month, it was also reported Liam was spotted ''locking lips with a random brunette'' at a New York nightclub, although his representative denied this was true.