Oscar-winning actress Julia Roberts has reportedly suffered an emotional breakdown after her mother was diagnosed with cancer.

Doctors found a cancerous tumour on Betty Lou's lung during a routine MRI scan and everyone went frantic with the sad news, reported Daily Mirror. Her mother had the disease in November, just months before Nancy Motes took her own life.

"Everyone was frantic because Betty has a history of smoking and emphysema... Julia has now suffered an emotional collapse. She was already reeling from her mum's cancer crisis.

Now, she's been deeply hurt and stung by all the criticism after Nancy's death and feels she doesn't deserve it," a source said. Betty was previously married to Walter Grady Roberts before divorcing him and giving birth to Nancy with second husband Michael Motes.