Born and brought up in Ayr, he became a distinguished civil engineer in both Scotland and the Far East. But he will be best remembered as the man who tracked down the grave of Scotland’s legendary athlete, who died in a Japanese prison camp in 1945.

It was while working in Hong Kong in the 1980s that Mr Walker became fascinated by the story of Eric Liddell, the Edinburgh University student who refused to run in the 100 metres in the Paris Olympics of 1924 because the heats were due on a Sunday.

With his deeply-held religious principles, Liddell switched to the less-familiar 400 metres – but scored a memorable success by winning the gold medal.

His remarkable story was told in the film Chariots of Fire, which gained the Oscar for best film in 1981. Liddell’s subsequent life as a missionary in China in the 1930s was as inspiring as his Olympic feat of 1924. But it ended when he was interned by the Japanese in a prison camp in northern China. For the

second time, Liddell became a legendary figure, revered for his selfless work with young and old within the camp. But at the age of 43 he died from a brain tumour shortly before the war ended in 1945.

All evidence of his grave disappeared. But Mr Walker set out to find it and, by a stroke of luck, found a fellow internee of Liddell – the man who had dug the grave.

Marking the spot on a map of the old camp, he visited, with a Mandarin-speaking friend, the school now occupying the site and managed to pinpoint in 1989 the location. With the help of Edinburgh University, a two-metre granite stone from Mull was transported to the school and erected as a permanent memorial to a great hero.

In 1991, it was unveiled in the presence of 45 devotees of Liddell, including his own niece and 10 former internees from the prison camp.

With a fine sense of history and occasion, Charles Walker brought back to public attention an array of other distinguished fellow countrymen in a splendid book A Legacy of Scots, which he dedicated to another Scottish legend, Jane Haining from Dumfries, whose missionary work landed her in Auschwitz, where she died in 1944. Mr Walker’s wife, Elizabeth, contributed the chapter on Jane Haining.

His interest in the Covenanter movement of the late 1600s spawned screen and radio scripts, while back in his own profession, he was the co-author of a text book on privatised infrastructure which remains in print some 14 years after being first published.

After Ayr Academy and a BSc in civil engineering from Strathclyde University, Mr Walker joined Edinburgh City Engineers’ department in 1968. At a busy time for construction, he was much involved in supervising road, bridge and sewage schemes.

But in 1977 he and Elizabeth moved with their young family to Hong Kong, where he worked for Maunsell Consultants Asia on the prestigious Sha Tin New Town project. He was also on the management team on the approach links to Hong Kong’s new airport followed by a container port construction in Malaysia.

Back in Scotland in 1997, he joined the Scott Wilson team overseeing the upgrade of the M6/M74 motorway. In 2001, Mr Walker joined the Halcrow Group in Edinburgh as a contract specialist, where he remained until recently.

Sadly, in 2006 he was diagnosed with cancer, which he believed he would overcome. But it returned last year. He was a special spirit, a man of good company, sound and balanced advice, with a proud commitment to his family.

In June, he celebrated his family bonds and friendships with a rather unusual event – a pre-wake gathering. People came from as far afield as Auckland, Sydney and Dubai, as well as across the UK as he said his last goodbyes.

He is survived by Elizabeth, four children and six grandchildren.