Wikipedia founder Jimmy Wales has announced the implementation of stricter editorial practices in the English edition of the free online encyclopaedia.

Wales said in a statement that he has experimentally removed the ability of unregistered users to create new articles in Wikipedia.

Unregistered users will still be able to fix spelling mistakes and add to existing articles, but are required to register a user account before creating new pages.

"This will reduce the workload on the volunteer editors controlling contributions to the project," said Wales.

"Our main goal is to produce a free high quality encyclopaedia. The 'open editing' process is a means to this end which allowed us to build Wikipedia and make it available to everyone free of charge. It is not a goal in itself."

Concern over editorial accuracy has become a key issue since the recent media coverage of a complaint in USA Today by retired journalist John Seigenthaler.

Seigenthaler discovered insinuations in his Wikipedia biography that he had been involved in the assassinations of both John and Robert Kennedy. After contacting Wikipedia this version of the article was immediately removed from the site and has since been rewritten.

Like many of the problematic contributions to Wikipedia, the offending version of the Seigenthaler article was written by an unregistered user. Wikipedia volunteers patrol a large volume of contributions in an effort to eliminate such problems.