NEW YORK >> NBC said it worked with Olympic officials to stop some 45,000 instances of illegally posted video or pirate streams that surfaced to show competition during the Sochi games.

The chase after video pirates operates in the shadows with an intensity all its own. Broadcasters pay big money to the International Olympic Committee — in NBC’s case, $775 million for Sochi — in return for exclusive TV and streaming rights and guard that exclusivity keenly.

Officials estimate that 20,000 videos of Olympic competition were kept off YouTube, either through filtering technology that prevents them from being posted in the first place or locates and takes them down shortly after they are added. Another 20,000 were stopped from distribution on similar video-sharing sites popular elsewhere in the world, like Dailymotion in Europe or VK.com in Russia, NBC said.

The hunt went beyond the traditional video-sharing sites. Buzzfeed said NBC contacted the website after it posted some figure skating video and asked that it be taken down, and the site complied.

The anti-piracy police also said they located and stopped an estimated 5,000 illegal streams of Olympics material, often live competition.

Many of them were posted on for-profit rogue websites that offer consumers material they could not get legally. Through its own websites, NBC streamed every competition live and offered many highlights, but consumers could not get access to this material without proving they were either cable or satellite television subscribers.

There was also a black market for streams of television coverage from various locations. For example, some links would give consumers in the United States a chance to watch the BBC’s coverage, or let people watch what NBC was doing while they were in a European country.

NBC tempted pirates from the very beginning, when the network chose not to televise or stream the Sochi opening ceremony live, instead showing edited highlights in prime time. This led many people who were interested to seek out illegal streams operating online.

NBC was not able to say how this level of detected piracy compared to efforts during the London Summer Olympics in 2012, or the Vancouver Winter games in 2010.

During the Olympics, officials estimated that 98 percent of online viewing of competition was done through legal channels.

“When all the players in the digital ecosystem cooperate and work together, it is possible to create an online environment in which legitimate commerce thrives, jobs are created and consumers receive content how, when and where they want it,” said John McKay, NBC spokesman.