Although many of us hoped that Sony would show off its upcoming Xperia Z4 handset at CES 2015, it just wasn't to be, but the phone might have been glimpsed by a select few behind closed doors.

According to self proclaimed 'Teknological Secret Agent' Twitter account, @Ricciolo1, Sony didn't show any smartphones to the public but something was shown "in the secret room".

This isn't the first time that a company has chosen to show a device behind closed doors to a select number of people on condition of complete secrecy, and the @Riccolo1 account has a decent track record for Sony leaks, so it could be that Sony has indeed shown off the Xperia Z4 (or another handset) in private.

Private showing

Why would Sony choose to show the Z4 off in private rather than publicly? We've heard rumours that the Z4 could be launching early this year, but it might not be ready for a full unveiling this early.

Instead Sony might be keeping its powder dry for a showing at Mobile World Congress, which runs at the beginning of March.

By showing the handset off in private, Sony could be keeping a select few updated about the progress of the device without showing an unfinished prototype to the rest of the world.

Hopefully we won't have too much longer to wait to get a proper look at the Xperia Z4.

• Sony Xperia Z4: what we want to see