Microsoft has alleged that Google is preventing it from offering a fully functional YouTube app on its Windows Phones platform.
Microsoft has said Google is unwilling to allow it to bring a fully featured YouTube app to Windows Phone because of its search competition with Microsoft.
"We continue to be dogged by an issue we had hoped would be resolved by now: Google continues to prevent Microsoft from offering consumers a fully featured YouTube app for the Windows Phone," wrote Microsoft's vice president and deputy general council Dave Heiner in a blog post.
According to Heiner, Google's is forcing Microsoft to use an outdated version of the YouTube app on Windows Phones. Windows Phone's current YouTube app is only able to browse the YouTube mobile website, so lacks functionality found on Android or iOS apps.
Microsoft reported it currently has a fully operational Windows Phone YouTube app ready. However, the firm says Google will not allow Microsoft to release it to the platform.
Google has rejected Microsoft's complaints, claiming it has been helping Microsoft on any issues for several years.
It said that Windows Phone users can access YouTube using its HTML5-enabled mobile site, which Google claims offers all of YouTube's key features.
"Contrary to Microsoft's claims, it's easy for consumers to view YouTube videos on Windows phones," a Google spokesperson told V3.
"Windows phone users can access all the features of YouTube through our HTML5-based mobile website, including viewing high-quality video streams, finding favourite videos, seeing video ratings, and searching for video categories. In fact, we've worked with Microsoft for several years to help build a great YouTube experience on Windows Phones."
Microsoft and Google's issues come as the two firms continue to fight a search war through regulators. Last year Microsoft issued a formal complaint to the European Commission alleging that Google was breaking antitrust laws through its search practices.
Google is also currently fighting an antitrust case with the Federal Trade Commission in the US.