Billy Ray Cyrus says his daughter Miley Cyrus is the ''happiest she's ever been in her life'' since splitting from Liam Hemsworth.

Miley and her actor fiancé called off their engagement in September following months of attempts to salvage the relationship which had been on and off since they met on the set of their film 'The Last Song' in June 2009.

'Achy Break Heart' singer Billy Ray says rather than wallow in self-pity about the failed romance his 20-year-old daughter seems to have a new lease of life.

During an interview on 'Entertainment Tonight' on Monday (07.10.13), he said: ''All I know for sure is I heard my daughter say today she's the happiest she's ever been in her life immediately following (the split) ... Somewhere along the stress and strain of different things I didn't see her smiling as often for a little while and, all of a sudden she's like the sun and when she smiles it's light ... Everything happens for a reason and the main thing for me, as Miley's daddy, is she's happy.''

Billy Ray did admit that Miley has been causing a lot of controversy lately with her twerking at the MTV Video Music Awards, racy photo shoots and tongue-in-cheek 'Saturday Night Live' hosting appearance.

However, the 52-year-old country musician - who also has two other children Braison, 18, and Noah, 13, with wife Tish -insists the former 'Hannah Montana' star has never had a normal life and neither has he.

He said: ''I've never known normal. Miley's never known normal. Noah might be [the closest] to all of our children as knowing normal and even that's quite sad to say, because let's think about her world right now. It's anything but normal ... I've really enjoyed the time I've been allowed to spend with Noah lately.''

Billy Ray also has a son, Cody, 20, from a relationship with Kristin Luckey and he adopted Tish's kids Trace, 25, and Brandi, 23, from a previous relationship.