Doubts are growing over the accuracy of statistics released yesterday claiming that Star Wars Kid is the internet's most watched video.

Vnunet.com has learnt that data supplied by The Viral Factory – which places Star Wars Kid at the top of its list of 10 most watched internet videos – was calculated using only an "informed approximation" of the number of people who emailed the videos to each other. This data was combined with information from video sharing sites.

The Viral Factory's estimate of 900 million views for the video was reached by "adding up views from a number of different sources combined with an informed approximation," Toni Smith, head of strategy and communications at The Viral Factory, told vnunet.com in an email.

"At this time it was more commonplace to send around video attachments via email to friends, something which we are unable to track exactly," she added.

"However, we approximate that it has been emailed around 600 million times over the last three years, with many people watching it more than once."

Video sharing sites are said to account for the rest of the total.

"We found over 90 million views on video sharing and community sites such as MySpace, You Tube and Google video. Most of these sites have only been around for a couple of years," Smith said.

"There are over 2.7 million Google search returns of websites linking to Star Wars Kid and views from video archive websites such as College humour, Kontraband, etc total to a further 250 million."

The top ten videos were:

Source: The Viral Factory for UKTV G2 Totally Viral