The propaganda of the Japanese prison camp in Borneo during the second world war!

The picture above is not all it seems – it was set up as a piece of propaganda from a Japanese prison camp in Borneo during the second world war, featuring Sarah Hilary's mother and grandparents.

Sarah Hilary

I'm sitting next to my grandmother looking through family photograph albums (a favourite pastime since I was tiny) when I find this picture. I haven't seen it before and wonder why it's not in a frame on the wall. It's such a great family photo. I ask my grandmother, who is on the right in the picture, but she can't look at it. She doesn't want to talk about it, although she already has, I realise – when I was a small child sitting with my siblings on her bed, listening to stories of our mother's childhood.

This is a photograph from the prison camp where they were held during the second world war. Like the tales our grandmother told us, it's only half the story because the camera lied.

"All is well," it lied. This is northwest Borneo under Japanese rule. The child is my mother, seated on my grandmother's lap. The man whose face is only glimpsed is my grandfather. I never knew him.

Thousands of people have seen this photograph. People on the other side of the world saw it, when the world was fighting a war of morale and conscience. People I will never meet have seen it. But my grandmother can't look at it. "Look at this happy family," it lies, when the family is imprisoned, impoverished, in fear of their lives.

The photograph was taken in the spring of 1944, two years after the Japanese invaded Borneo, capturing the men, women and children of unfriendly nations, Chinese, Dutch, British and Australians among them, to be interned in camps on the third largest island in the world. By 1944, many of those interned had died; more were dying.

Domei News, then Japan's only news agency, dispatched reporters to the frontline in Asia and the Pacific. They sent home almost daily the Domei Photo News, which was distributed by the thousands to schools, factories, shops and public places. The Domei News photographer's task was simple: show the world how content our prisoners are. The photos were intended to appease organisations such as the Red Cross, and convince ordinary Japanese families that the war was being fought honourably.

My mother was Emperor Hirohito's poster child.

No one in the photograph is wearing their own clothes. The white shirt, flowered dress and child's pinafore were loaned by the Japanese and taken back at the end of the photo shoot. My grandmother was made to wash the makeup from her face before returning to the women's camp, where no new clothes or makeup had been seen in two years. As one internee wrote in the diary she kept hidden from the Japanese: "My last towel has now disintegrated, so after washing I am obliged to shake myself like a dog until dry."

If you look closely at the photograph, you'll see that my mother is wearing a crucifix. It was carved by the Roman Catholic sisters in the camp, from the Perspex windshield of a military aircraft. I have my mother's crucifix to hand as I write this. It is small, light; pleasingly tactile. 

A stranger finding it in a house clearance would think it worthless and throw it away. The same stranger might linger over the heart-shaped pendant, also painstakingly carved from Perspex by the nuns, who placed tiny pictures of my mother's parents, no bigger than a thumbnail, into the hollowed heart of the necklace. They did this same kindness for every child in the camp.

Prisoners at a Japanese POW camp in Borneo

Other memorabilia survive. A tin the children ate their meals from, toys stuffed with rags and sand, a book whose margins are filled with appointments pencilled by my grandmother, who was hairdresser for the women and children. In the same book: tallies of cigarettes to be bartered with the guards for food and other necessities.

My grandmother was 25 and a young mother when she was taken prisoner. Her courage still humbles me. I can't imagine surviving a fate like that, never mind keeping a small child alive and well. Whenever I suggest this idea of courage to my grandmother, she shakes her head, but she will admit that the experience made her stronger.

I expect the Japanese photographer tried to win a smile from my mother. Her unhappy expression is a small victory against the casual cruelty of the propagandists. She was taken from her home and loaded on to a truck with dozens of other children and their mothers, shipped to an island leper colony and then by boat to a prison camp where she saw brutality and disease, knew hunger and witnessed death. She saw men dig their own graves. She saw sons dig graves for their fathers. She was not yet five. Within a year of this photograph being taken she would be gravely ill with pneumonia and her father would be dead.

Her father, my grandfather, whose face is in shadow in the portrait, risked his life with a group of comrades to spread forbidden news of the war to the other prisoners, news such as the death of Hitler, information that kept many prisoners alive and hoping, long enough to survive until liberation. For doing this my grandfather was taken to a military prison where he died of malaria before he could be executed, with his comrades, by the Japanese.

The dropping of the Hiroshima and Nagasaki atom bombs in 1945 ended the war in the far east. I feel a queasy sense of survivor guilt at the thought that without those atrocious bombs, I wouldn't be here to tell my grandmother's story. No one in the photograph, no one in the prison camp, would have survived the orders from the Japanese high command, to burn the women and children and to bayonet the men.

On 11 September 1945, the camp was liberated by Australian troops. Because my grandmother had sold her engagement ring to a guard in exchange for penicillin, my mother survived to see the liberation, to watch with the other children as thousands of red, white and blue leaflets dropped from Allied aircraft into the camp, telling the prisoners to "Be of Good Cheer" and that rescue was on its way.

Another photo, smudged and grainy, shows my mother (then six and smiling) in the arms of an Australian soldier. There are no snapshots of my grandmother in the days immediately after the liberation. She was trying to find her husband. She didn't know, then, that he had died.

For a long time, I kept my grandmother's story a secret. As she did; returning expatriates were told not to talk about their ordeal, for the good of morale in postwar Britain. Many never spoke of it. My grandmother never talked with her daughter about their ordeal, believing it a blessing that my mother remembered so little of it. Thinking, in fact, that my mother remembered nothing (she remembered snatches). The silence was a kindness, an act of faith between them, to keep the horrors of the past at bay.

Only when she had grandchildren did my grandmother start to tell her story. Gently and with humour, setting the horror aside so that we could not have guessed that we were hearing about nearly four years of imprisonment, the constant threat of sickness and death. Every day, in the final years, the children in the camp saw the same flag used to cover coffins of the dead.

My grandmother told stories of happy Christmases, our mother learning to write with a stick in the sand, running barefoot, everywhere. We were enthralled, always begging for more, not knowing until we were grown up that there was a secret to the story. I remember the day it clicked into place in my head, vividly and with a sensation like vertigo: a familiar landscape suddenly seen upside down, inside out.

My grandmother died in November 2000. She was the best and bravest of women. I remember her sense of mischief and adventure. She inspired so much of what I do. If, as she believed, her spirit was forged in the fire of the prison camp, then it was an indomitable spirit, full of love for life and, yes, courage. She knew I wanted to be a writer so I hope that she told me the story of the prison camp because it needed to be told. Needs to be told.

The Domei News Agency was disbanded in 1945. It had served its purpose. Thousands of photographs had convinced millions of people that all was well. Just as Allied propaganda convinced millions of others, of the necessity of dropping the atom bombs.

Once you know the truth, it becomes hard to look at the photograph, perhaps because the truth is so obscured by the horrific realities of the time. Each time I see it, I feel something different. Loss of course, and grief. Pride for my grandfather's sacrifice and regret that I never knew him and because my mother grew up without her father; deep sadness for my grandmother's loss, and my mother's. Gratitude for their survival and the happiness they brought to my life. And wonder that two human beings could live through trauma of that magnitude and not be bitter or timid but instead huge-hearted, generous and tender. All that I know about the strength and value of families, I learned from them.

I began by saying that this family photograph lied, but perhaps I'm wrong. Perhaps, despite the borrowed clothes and the studio pose, the photograph shouts a great truth, about love and survival and the unassailable nature of the family.

Written by Sarah Hilary on The guardian