Eric Liddell exhibition for champion who wouldn't run on Sundays

Eric Liddell rarely spoke of the extraordinary day in 1924 when, head thrown back, arms flailing, he won the 400m gold at the Paris Olympics – but his small daughters realised there was something special about their father the day he caught the rabbit.

Liddell's dazzling speed, and the Christian faith that led him to refuse to compete when the heats for his original 100m distance were held on a Sunday, became the heart of the Oscar-winning film, and remarkable stage adaptation, Chariots of Fire.

"My mother said he always told her: 'I was not the fastest man, I was the fastest man on that day,'" Patricia Russell, his eldest daughter, said.

Russell was on a nostalgic visit from her home in Canada to the UK to study a large archive of letters, photographs and documents relating to her father, which will be seen in an exhibition on his life, The Man Who Would Not Run on a Sunday, in July at the School of Oriental and African Studies (Soas) in London, and to see the play.

In 1940, the last summer his family would spend together, he was on leave from his mission station in China with his Canadian wife, daughters Patricia, five, and Heather, four, at his sister's home in the countryside outside Edinburgh. "We were out for a walk one day and we saw a rabbit – and you know in those days of the war, a rabbit for the pot was a great thing – so he ran and caught it in his hands and killed it," Russell recalled 72 years later. "We were most impressed, but then Heather – she was very little – said, 'Now put it together again, Daddy.' He turned to my mother and said, 'Well, I won't be doing that again.'"

The family returned to China, but in 1941 Florence became pregnant again, and the decision was taken that she and the children should return to Canada. Liddell chose to stay where he felt most needed, but had no doubt they would meet again.

Russell said: "I was a rather solemn, serious child. My father brought us to the ship, and I remember him taking me on his knee and saying, 'Look after your mother and help her with this new baby until I return.' I'm sure if he had any idea he was not returning – he would not have said that.

"And then," Russell recalled, "Pearl Harbour happened, and everything changed."

Liddell never saw Maureen, the new baby. He spent most of his life as a missionary in China, like his father, grandfather and brother, and died of a brain tumour in a Japanese prisoner of war camp there in 1945, months before the end of the war.

Among the documents Russell pored over in the archive, which came to Soas from the London Missionary Society, was a moving letter from the man who occupied the bunk below him: "When Eric came home with a bad headache and went to bed, I did what little I could for him. I was able at least to smooth out his bed and fix his pillow, and see that his food was fixed nicely.

"During that little spell when he was feeling better, he had a feeling that he had neglected his family, and brought out several photographs of you and the children and put them where he could see them often. Truly, I think he was the finest man I've ever known. He was like a father to me and I his naughty boy."

It was mainly for the children on the mission station and later the camp that Liddell stayed. The archivists at Soas have had visitors who remember Liddell's classes, games and entertainments as all that kept them going through those terrifying years.

Russell recalled that her father had chances to leave before the Japanese invasion. Once a ship had space for all the mission station people, but they arrived at the quay to find wealthy merchants had bought their places.

Neither her father nor her aunt Jennie were as fierce and dogmatic as portrayed in Hugh Hudson's 1981 film, she said. "My father was a man of deep faith, but he would never force it on anyone else. He would not run or play ball on a Sunday, but he would never have stopped anyone else from doing it."

When Jennie saw the film, she rang the family in Canada and said sadly: "They've made me out to be a right proper primmie".

Russell loved the stage adaptation – "It was wonderful, full of passion," she said. After a sell-out season at the Hampstead theatre, in north London, the play is transferring to the Gielgud theatre in the West End. Her father is touchingly played by the young Scottish actor Jack Lowden, who must sprint the best part of a mile during the show on the running track startlingly incorporated in the set.

The play follows the film closely, but introduces a new character – Russell's mother, Florence, portrayed as a feisty young Canadian nurse who meets Liddell at the Paris games and has the inspiration to get him out of Sunday running by transferring him to the 400m.

"You know, my mother was 10 years younger than my father, and she was only a child in China when he was in Paris," Russell said, laughing.

"Hugh Hudson [the film's director] rang me to ask about putting her into the play. I said if Eric is going to have a fling in Paris, by all means let it be with my mother."