Fauja Singh, a 100-year-old runner who attracted worldwide attention when he completed a marathon in over eight hours, won't be recognised as the world's oldest marathoner because he can't show a birth certificate. Guinness World Records said it won't recognise Singh, a Briton of Indian-origin, as the world's oldest marathoner because he can't show a birth certificate from 1911. The editor-in-chief of Guinness World Records, Craig Glenday, was quoted by the BBC saying that, they would love to say that it is a true Guinness World Record, but there is no evidence. He said they can only accept official birth documents created in the year of birth.Singh, who only speaks Punjabi, was the last competitor to complete a full-distance 42-kilometre marathon.