With no mobile phone or any way of being contacted, he was unaware he had won until he was on his way back to his home later that afternoon.
He said an elderly woman who introduced herself as a former neighbour stopped her car and got out to congratulate him, saying she had been told he had won by her daughter in London.
The Nobel Prize Committee in Stockholm had tried in vain to contact Professor Higgs on Tuesday to tell him he had been awarded the prize.
Speaking at a press conference at the University of Edinburgh yesterday, he said: “At the time of the announcement, I was down in Leith for lunch. I had originally intended to be in the West Highlands but that didn’t come through. So, I got out of the way for a period on Tuesday morning while the telephone messages mounted up. I heard the news when I was returning from my lunch later in the afternoon.”
He added, “As I was walking a car pulled up across the road and a lady got out and introduced herself as a former neighbour, and congratulated me on the news.
“I said ‘what news?’ and she told me that her daughter had phoned from London to alert her to the fact that I had got this prize.”