Gemma Arterton's gran died after stabbing herself through the heart

Inquest concludes Helen Sarfas committed suicide

Gemma Arterton's gran Helen Sarfas killed herself in January

Gemma Arterton's grandmother stabbed herself to death, it emerged yesterday.

A coroner's inquest in Maidstone yesterday ruled that Helen Sarfas, 69, committed suicide after a long battle with depression.

The 69-year-old - who was bipolar and had osteoarthritis - was found in bed with a knife in her heart by husband Rodney Peacock, 85, at their flat in Gillingham, Kent, in January.

'She was suffering severe pain from osteoarthritis and her joints,' coroner Roger Sykes ruled.

'I can only reach the conclusion she took her life because the physical pain and depression became too much.'

Gemma, 24, was in West End play The Little Dog Laughed when she was told of her Helen's death.

'This is a private family matter,' her spokesman tells the Daily Mail.

Gemma's new movie Tamara Drewe is out now.