The online encyclopaedia Wikipedia should be taken with a pinch of salt, a spokesman insisted today.

Wikipedia founder Larry Sanger told The Times it contains "frequently unreliable content" and is "broken beyond repair". But Wikipedia’s UK spokesman David Gerard said critics take it too seriously. He said: "The problem is that sometimes people take us to be more reliable than we are. If you read it with critical thinking you’ll get value out of it. It’s not reliable in that you can trust every word."

Wikipedia bills itself as the "free encyclopaedia that anyone can edit". It is an internet phenomenon, publishing information in more than 100 languages and has more than 1.7 million English-language articles.

Its egalitarian nature is the secret of its appeal. Contributors are less likely to be tweedy academics than the office know-it-all who has found an outlet for his obscure passions. Anyone can write about anything.

Famous gaffes, as reported in the UK press, include reports that ex-Wet Wet Wet frontman Marti Pellow had died and the ridiculous story that the Irish town of Mayo had acquired a militia to fight off werewolves.

There have also been cases of "vandalism" where bogus or abusive information has been posted, although errors are removed.

Mr Gerard said: "Every single objection you can think of actually happens and we deal with it.

"Wikipedia is more reliable than it ever was but you can’t get away with not thinking. Anyone can edit it."

David Bawden, a senior lecturer at the School of Informatics at London’s City University said: "It’s not something that you should rely on, certainly, but you shouldn’t rely on any single information source.

"It’s one of a number of internet resources like Google, MySpace and YouTube which gets seen by people and somehow a momentum builds up. It has got more people thinking about information and knowledge and how you get it.

"My approach is, ‘it’s good but...."’

Mr Gerard said the secret of Wikipedia’s success is being "painfully open".

He said: "Instead of controlling stuff we tend to let stuff in and then fix it when it’s wrong. You get bad stuff but you get a lot of good stuff you wouldn’t get otherwise."

The German Wikipedia site is considered to be far more reliable as more fact-checking goes on, he revealed. He said: "The English site has occasional hiccups in quality but its strengths are its incredible breadth of coverage and it is reasonably up to date."

Mr Bawden said: "Some bits are kept up to date by world experts, others are written by people with a personal view. You should take it as a very useful first resource."

Mr Sanger has launched a similar venture called Citizendium.org which promises greater accuracy.