Microsoft is working on virtual reality devices for Xbox, according to the Wall Street Journal.
Sources familiar with the project said the technology has been developed concurrently with the Fortaleza project, which is thought to relate to augmented reality glasses.
The Wall Street Journal's report suggests one version of the new tech is also based on augmented reality. Could the virtual reality device in question and the Fortaleza project be one and the same?
The rumour comes ahead of an expected reveal of Sony's virtual reality headset for PlayStation at the Game Developers Conference tonight.
Oculus VR's Oculus Rift headset is already at the developer kit stage. A consumer version is in the works.
Backing up the rumour that Microsoft has its own device in development is a patent filed by the company in August 2013 that relates to "multiplayer gaming" with a "head-mounted display".
Back in June 2012 a document reportedly created by Microsoft was published by The Verge. In it, what was apparently Microsoft's roadmap for what would turn out to be the Xbox One was outlined. It included reference to Project Fortaleza, aka Kinect Glasses, which were, at the time, planned for release in 2014.
A Microsoft spokesperson declined to comment when contacted by Eurogamer.