He was born in Clapham, south London, during World War II and some of his earliest memories are of the Blitz. Neither of his parents was religious. His school was nominally Church of England, but during scripture classes he was always, as he put it, "the number one sceptic". He graduated in Modern History from Magdalen College, Oxford.
He first came across the Shroud during the 1950s, when he was in his mid-teens, in an illustrated article by World War II hero Group Captain Leonard Cheshire. It was the famous image on the negative of the Shroud that dealt the first blow to his formerly complacent agnosticism. In 1972 he converted to Roman Catholicism.
He participated in the three part 1984 Channel 4 TV series Jesus: The Evidence and wrote the accompanying book of the same name. 
He lived in Bristol, England, for twenty-six years and now resides in Brisbane, Australia, with his wife, Judith. They have two sons, Adrian and Noel.