Norris McWhirter, who founded Guinness World Records with his twin brother and turned the book into a global best seller, has died age 78.

McWhirter suffered a heart attack on Monday 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 went to top 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- including the world's fastest chicken pluckerto the tallest man.

McWhirter's family said in a statement: "Norris cared passionately about Great Britain, democracy and the rule of law and was always active in politics, but usually behind the scenes".

"The two things he attached most importance to were the freedom of the individual and the sovereigntyof the United Kingdom," they said.

Outside their publishing careers, McWhirter and his brother Ross were active politically and founded the Freedom Association, a right-wing group that campaigned against British involvement in the European Union.

Both brothers held strong political views. Ross was assassinatedby the Irish Republican Army (IRA) in 1975 for his outspokenopinions on the turbulentsituation in Northern Ireland.

The killing shocked McWhirter, but he maintained a high public profile with appearances on the BBC children's show "Record Breakers and later wrote a book criticising the European Union.

He ended his editing career at the Guinness book in 1986 but stayed with the publishing phenomenon for another decade in an advisoryrole.

He leaves a wife and two children.