Mail Online has unearthed a picture that shows the the then 11-year-old Roberts posing for a family Christmas card while her allegedly 'abusive' stepfather Michael Motes stands stony faced behind with her cigarette in hand.
Years later that unmistakable smile would captivate audiences around the world – but even as a child it appears Julia was good at putting on a show.
'Despised': It's widely held that Julia Roberts 'feared' her step-father Michael Motes though she's never spoken about it, here she smiles bravely in front of him as the family picture is taken for a Christmas card. She is 11.
Young Julia is said to have 'feared and despised' alcoholic Motes who is said to have made her and her siblings lives a misery, though the actress has never spoken about him publicly.
Now as the star promotes her Oscar-tipped movie August: Osage County - in which she plays an adult daughter returning home for her father's funeral and coming to blows with her dysfunctional family - Mail Online can reveal Julia's real life childhood demons could soon be coming back to haunt her.
In an exclusive investigation into Julia's childhood in Smyrna, Georgia Mail Online tracked down her stepdad Motes who she has always refused to speak about.
Uncovering this exclusive first ever photograph of Julia and Motes together, we can reveal the 68-year-old is now planning a tell-all memoir about their past that is set to horrify the superstar who has done her best to forget she ever knew him.
Christmas greetings: Pictured L-R is Nancy Motes(Julia's half-sister), Betty Lou Motes (her mother), Lisa Roberts (her sister), Michael and Julia
Good little actress: With her home life allegedly so difficult, Julia learned to smile on cue at an early age
That smile! Julia's trademark grin was evident at a young age
Motes was married to Julia's mother Betty for 11 years between 1972 and 1983. Betty cited 'cruel treatment' in her divorce petition and has since called their marriage 'the biggest mistake I ever made.'
Julia's older brother, Runaway Train actor Eric Roberts, has also given several interviews claiming Motes was 'abusive.'
Our exclusive photos shows Motes as he looks today, more than 30 years since he moved out of the family's home. Now living in obscurity in Marietta, Georgia - just 13 miles from the house in which he raised Julia - most people have forgotten he once brought up one of Hollywood's biggest ever stars.
Mail Online can reveal Motes, a retired antique dealer, now lives with his male partner Timothy Raasch and is a volunteer minister at his local church.
However when approached about the allegations he gave Julia an abusive upbringing, Motes declined to provide an interview and revealed he is writing a book.
Stunning: The actress was raised by Motes but never speaks about him
Star appeal: Julia's movie star looks have barely changed over the years
'70s gal: Julia's auburn locks were styled in some epic variations when she was a teenager
He said: 'I do not give interviews. I don't have to justify my answer, the answer is no. I won't talk at this time.
'I didn't then (when the allegations first came out) and I do not now. There are a lot of misconceptions. I'm writing a book about my life that will tell my side of the story...'
Despite Motes not wanting to speak about their past, Mail Online obtained this haunting never-before-seen photo from Christmas 1978 which shows the family posing in front of the fireplace in their home.
Mum Betty, 11 years older than Motes when they got together, holds their daughter Nancy, then aged three. In the middle is Julia's older sister Lisa, then 13.
A year earlier Julia's biological father Walter Grady Roberts had tragically died of throat cancer aged 44. Walter and Betty had divorced in January 1972 and just eight months later she married Motes.
Humble beginnings: This is the home in Smyrna, Georgia where Julia was raised
Basic: This is Julia's old bedroom, it's now an office
Consequently Motes was Julia's stepfather from the age of five to 16 and once Walter died in 1977, when Julia was just 10, he was the only father figure in her life.
In August: Osage County Julia stars alongside Meryl Streep, who plays her mother, and in one scene they end up brawling on the floor after an argument.
Both are already being tipped for Oscar glory and Julia has already won the Hollywood Supporting Actress Award at last week's Hollywood Film Awards for her performance which has been described as 'brilliant and passionate.'
From her brother Eric's accounts of what their real childhood was like it isn't hard to see where she may have drawn her inspiration for the role.
Past she'd rather forget: Julia (left) and sister Lisa (right) were pictured in the local newspaper
Good Samaritans: The girls were cleaning gravestones for Confederate soldiers, the Confederate flag is now associated with racism due to the Confederacy's historical support of slavery
In a past interview Eric Roberts has said: 'It was common knowledge where we grew up that Motes was a freak. He would have stood out in a crowd of ten thousand. Whether he married my mother to get close to her children or not, I don't know. But clearly, marrying him was not a good decision or a healthy thing for her children. Our Mother's husband terrorized and abused me, and I fear he terrorized my sisters, Julia and Lisa, as well.'
In the 2004 biography 'Julia: Her Life' by James Spada the author wrote how Julia 'feared and despised' Motes and that he "at least, alternately ignored, pushed around, and denigrated his two stepdaughters".
Nine years older then Lisa, Eric moved out soon after Motes married Betty but he was terrified his stepdad would hurt his sisters.
Planning a book: Michael Motes as he is today, pictured in Marietta, Georgia, he is intended to tell his story
No contact: Roberts has nothing to do with her step-father, and never speaks of him
In a 1998 interview he said: 'I was horrified when I thought about what my poor sisters were going to have to endure living with Motes.'
And the previous year he also told the journalist J. Randy Taraborrelli: 'The guy who raised us was f***ed up.'
When the journalist asked if Julia and her sister Lisa had a tough time with him, he added: 'I know they did. That's what I'm telling you. Who knows what they went through with this guy?'
Whatever the truth is about what Julia went through, she is bound to be upset by the idea of Motes bringing out a book.
A source close to the family told Mail Online: 'Motes is a former alcoholic and when he was drunk he was a nasty piece of work who would often have raging arguments with the mum Betty and the children.
Oscar buzz: Roberts, now 46, is busy promoting August: Osage County, which sees her character deal with issues from a painful past
Hard working: The actress, who now lives in New Mexico, is currently filming The Normal Heart in New York
'There were horror stories of how he once threw Julia's Walkman against the wall smashing it in a rage. Julia would often stay over at friend's houses to escape it. Motes didn't have a steady job and Betty was so busy working all the time to keep the family afloat.
'Julia never talks about him and frankly she probably would be happy if she never saw or heard from him again.'
The source added: 'Motes has subsequently come out as gay, lives with his male partner and even volunteers as a minister at his local church.
'It's now more than 30 years ago he was Julia's stepdad and hardly anyone in the area knows or remembers their connection. God knows why he wants to write a book but the idea he could recount such an unhappy part of Julia's life which she just wants to forget will surely horrify her.'
Motes abandoned the family completely soon after his divorce from Betty and no longer keeps in touch with any of them.