Miley Cyrus and Liam Hemsworth have reportedly split.

The couple - who have been dating since 2009 but separated twice in 2010 - have reportedly gone their separate ways after the former Hannah Montana star's partying ways became a "problem" for the Hunger Games actor.

One source said: "Miley and Liam are done; it's over. She likes to party really hard and can be pretty wild. It became a problem for him."

Another source told the New York Post newspaper: "They have broken up before, and are broken up again now. There was drama because she suspected he had a wandering eye. And she recently tweeted a denial that he cheated.

"While Miley has insisted they are still together, right now they are very, very much apart."

Liam - who proposed to the 20-year-old singer and actress last March - recently flew back to his native Australia to escape his problems and spend time with his brother Chris.

A source said: "He needed to get away from Los Angeles and spend some time with his brother and friends."

However, despite the split friends close to Miley - who was recently photographed without her engagement ring - are hopeful they will reconcile their differences and reunite once again.

One pal said: "Miley is a fiery character, and they do fight, but she is crazy about Liam. She isn't ready to accept it might be over for good."