For more than 50 years, Sam Purvis stayed silent about his three-and-a-half years as a prisoner of the Japanese, until finally entrusting the story to his nephew. Nick Morrison reports on the man who used football to save his comrades - and the enduring mystery of Yashata.

TO Ray Watson, his uncle Sam was a hero. To the young boy, this man who stood over six feet tall was a giant, but what gave Ray the right to brag about his uncle to his schoolmates in those immediate post-war years, was that Sam had been a prisoner of the Japanese.

But Sam never spoke about his years in captivity. The only outward sign of the scars those years had left was that when Sam came to visit, everyone was careful not to give him rice to eat.

Until eventually, after 20 years of persuasion, Sam told his remarkable story to his nephew. Of the horrors he had seen and the brutality he had witnessed, of the conditions he had endured and the pain he had suffered. But most astonishing was the extraordinary friendship he formed with a football-loving Japanese, and how Sam used his footballing ability to save the lives of hundreds of his comrades.

Now, six years after Sam's death, Ray has put the story down on paper for the first time, as testament to his uncle's courage and his efforts to help the sick, and to the power of sport in the grim hell of the prison camps.

Sam Purvis was brought up in Washington, Wearside, where his sporting ability shone as a schoolboy. His head teacher thought cricket was his stronger sport, but Sam concentrated instead on football. After leaving school, he signed as an amateur for Sunderland, then as a professional for First Division Middlesbrough.

After three-and-a-half years with the Boro, he transferred to Watford, where he spent another year before deciding at 22 to abandon the life of a professional footballer and train instead as a nurse. He had been nursing for just a few months when war broke out, and a few months later still was called up, joining the 197th Field Ambulance.

After twice crossing the Atlantic, he was posted to India, and in February 1942 set sail for Singapore. But it was to prove a fateful trip. As his ship, the Empress of India, approached the island, it was attacked by Japanese bombers and sunk. Sam escaped, but it was a short-lived reprieve. Within days of arriving in Singapore, the island had been overrun and he was a prisoner.

His first introduction to his captors was an horrific one. He was returning to the hospital with supplies when he saw Japanese soldiers enter the wards with swords drawn.

"The soldiers started to slaughter the patients," he recalled. "It was an unbelievable sight and we were left gasping at the sheer horror and incredibility of that massacre. During all my time..., it was that episode of cruelty that stands out so painfully in my mind."

He was taken to a camp where conditions were appalling. With no running water and only rice to eat, dysentery was rife. Those whom Sam, his fellow nurses and doctors managed to cure of dysentery, often died of malnutrition. Most of the Red Cross medical supplies were confiscated by the Japanese.

"I have seen suffering, and I have buried the sufferers, and tears have streamed down my face at the terrible sights I'd seen. I never, ever dreamed how so many of my fellow men could have been so ill-treated," he told Ray.

Eventually, he was moved to Changi camp, where he continued working in the camp hospital. By this time, the prisoners had resigned themselves to a lengthy stay in captivity, and began to think of ways of keeping themselves entertained. Lectures were introduced, and Sam was asked to talk about his pre-war career as a footballer. His were among the most popular.

"The pleasure on their faces was a joy to behold," he said of his audience. "Question time was fabulous and one could have given any answer and still receive a standing ovation. I enjoyed those lectures so much and I gained a lot from doing them."

The prisoners also started to organise football matches. Playing the full 90 minutes, the prisoners ran their own league, even organising international matches which attracted crowds of thousands. The matches continued when they moved to Selarang camp in August 1943, and it was there that Sam attracted the attention of a Japanese officer.

"It so happened that a Japanese soldier had taken an interest in me. I was to understand, through his interpreter, that he thought I played football very well and had watched me many times in Changi. He wanted to know if I would teach him to play football," Sam said.

So Sam started to teach the soldier, whose name was Yashata, to play football. Yashata, who called his teacher Mister Sam, seemed to occupy a special position in the camp, coming and going as he pleased and shown respect by the other Japanese officers.

Sam's new role had its perks. After training, Yashata took him to the beach, where he taught him to swim, but it was the extra food that was most valuable. When Sam told Yashata that the prisoners had been stopped from playing football because they were too weak from hunger, Yashata organised extra rations, including the first tinned food they had seen in 18 months. On one occasion, Yashata brought 11 Japanese soldiers with him, to play a match against the prisoners. As the game wore on, it became obvious the Japanese had been ordered not to retaliate.

"I've never seen any of our lads enjoy themselves so much," Sam remembered. "They simply tore into the Japs and gained some sort of revenge for being captured. Never before had I seen so many fouls in a football match."

Sam's footballing skills meant he was spared being sent to work on the notorious Thai-Burma railway, estimated to have claimed a life for every sleeper laid. But he saw some of his fellow prisoners return from the railway.

"Never in my whole life have I seen such a heart-rending sight as met my eyes that day. To see those poor souls dragging their drained carcasses into that hospital filled my eyes with tears," he said later.

In May 1944, he was moved to Krangi camp, where he once again came across Yashata. But after passing on a sack of food and the knowledge that the Allies were winning the war, Yashata had more unwelcome news: that if Japan were to lose the war, the prisoners were to be beheaded.

"Yashata was a good friend to me and risked a great deal to tell me of the time and date of the forthcoming massacre. He would almost certainly have been executed for telling an enemy what he knew," Sam said.

Yashata also helped the prisoners get hold of wood when they had no fuel to cook their rice. Sharing the wood they cut with the Japanese also gained them extra food

"Many's the time I have said to myself, 'But for the grace of Yashata, I would have had to bow and scrape to get wood and the bare essentials for survival'. An awful lot of colleagues owed their lives to that man and his generosity."

In early 1945, as the prisoners saw US bombers overhead with increasing regularity, Yashata once again visited the camp. Again he warned of the fate facing the prisoners, but this time he had an unusual request.

"He told me that he didn't know if he would ever be able to return to the camp to see me again. He asked if I would write to him when I got home," Sam related.

"I told his interpreter that I couldn't write to him because of the atrocities that his Japanese counterparts had committed against my fellow countrymen. That alone forbade me to write to any Japanese. He was very sad but he obviously understood my feelings. We shook hands and I too was sad - very sad."

That was to be the last time he saw Yashata. A few weeks later, the war ended, and, perhaps shocked by the effects of the atomic bombs, the Japanese threat to behead their prisoners was not carried out. Instead, the guards surrendered.

Repatriated to England, Sam resumed his nursing career and married Enid, refusing to talk about his life as a prisoner until eventually persuaded by his nephew Ray, shortly before he died in May, 1999.

But the mystery of Yashata has remained. Despite his best efforts, including poring over records and advertising in newspapers, Ray, from Hartlepool, has been unable to find out what happened to the man who saved his uncle.

"I, for one, am grateful to him for looking after Uncle Sam and he may even have contributed to saving the lives of many of the prisoners in doing so," Ray says.