Norris McWhirter, who founded Guinness World Records with his twin brother and turned the book into a global best seller, has died aged 78.
McWhirter suffered a heart attack last night after playing tennis at his home in south-west England, the spokesman said.
The London-born son of a newspaper director, McWhirter was a writer, sports commentator, athlete and political activist but will best be remembered for co-founding the "Guinness Book of Records" - now known as "Guinness World Records" - in 1955.
The book of superlatives topped the British bestseller list that year and has since become a publishing phenomenon with sales of more than 100 million copies in 100 different countries and 37 languages.
It lists every world record from the breathtaking to the bizarre - such as the world's fastest chicken plucker.