JAMES McAvoy is heartbroken after his mum died aged 59 in her Glasgow council flat.
Liz Johnstone, 59, battled poor health for years and died in the town where James, 38, grew up, alongside his sister Joy, 35.
The family were reportedly close despite his loved-ones shunning the Hollywood limelight.
Liz, a psychiatric nurse, was estranged from James's dad, James McAvoy Snr, who worked as a roofer.
James, star of X-Men, Filth and the Last King of Scotland, regularly visited his family in the tough Scottish neighbourhood of Drumchapel.
A local source told Daily Record: “Liz had health troubles and faced up to them as well as possible but it meant she really kept herself to herself.
“She had no desire to change her life on the back of his fame. She wished to stay in Drumchapel and that’s what she did.
“She never ever held any airs and graces about James and Joy being on TV or in movies and she would play it down. But she was very proud of them both.
The source added: “Her parents have always been just the same and never wanted any fuss.
“They were proud of their grandchildren as any other grandparents would be.
“They are extremely nice and down to earth people and that probably helped keep James fairly grounded despite his big success.”
Joy starred alongside brother in 2013 movie Filth.
James had his big breakthrough in Channel 4 hit Shameless.
In 2016 he split with wife Anne Marie Duff, but stayed together in their £1.9million north London house with their son, Brendan.
A Police Scotland statement said: “Around 5.30pm on the 18th of January, the body of a 59-year-old woman was found in a property on Drumchapel Road.
“The death is being treated as non-suspicious.”
Last year, James transformed his physique by eating 6,000 calories a day and hitting the gym as he bulked up for psychological thriller, Split.