Videos removed at the behest of copyright owners accounted for only a small percentage of viewership on top online video service YouTube, according to a study published this week, drawing the ire of media companies that dispute this conclusion.

Less than one in 10 videos on the Google Inc.-owned (GOOG) site were uploaded without the permission of copyright holders, according to a study by online video tracking firm Vidmeter.com. Pirated clips that were pulled off YouTube attracted only 6 percent of viewers, the study found.

But media companies complained the study only counted videos that were removed as unauthorized content and not the myriad others, many of them duplicates, that escape attention.

The report comes amid a high profile $1 billion lawsuit filed by MTV Networks-owner Viacom Inc. (VIA) in March that charged Google and YouTube with "massive, intentional copyright infringement" and growing concern in the media industry over Google's clout.

"We have concluded that unauthorized copyright videos make up a relatively small portion of YouTube's most popular videos and an even smaller portion of views," the report's authors wrote.

Viacom called the study's findings and methodology "flawed." Privately, another media industry source also disputed the conclusions.

"The Vidmeter study undercounts the volume of copyrighted content on YouTube by a significant margin," a Viacom spokesman said in an e-mailed statement.

"Among other things, during the sample period, and even at present, many copyright owners had not sent take-down notices for their copyrighted material."

Vidmeter said it counted videos taken down by YouTube, with a page replaced with the content owner's name and not the myriad other clips that continue to reside on the service.

Clips of Viacom's "South Park" animation shows, for example, can still be found on the service, even after YouTube removed more than 100,000 clips.

Viacom said: "YouTube's site is designed in ways that make it impossible for rights holders to locate all of their copyrighted content, so even a robust take down notice program will miss significant amounts of copyrighted material.

The report studied video clips and usage over four months beginning in December 2006 and comprised a small subset of 6,725 most-watched video clips on YouTube.

Some 9.23 percent of videos on this list were taken down at the request of copyright holders that include Viacom, Time Warner Inc., News Corp. and Walt Disney Co.

About 2 percent of the scanned video clips were owned by Viacom. Also contrary to popular perception, the report found that music videos were among the most-viewed category.

"Even with these flaws, however, this study can put to rest Google's protests that it doesn't know about the massive copyright infringement taking place on YouTube," the Viacom spokesman added.

YouTube was not immediately reachable for comment.