Two photos published on Picasa Web Albums appear to have been taken with an Asus Nexus 7 tablet.

The long-rumoured, much-anticipated device, which is expected to be announced at Google's I/O conference later in June, was apparently used to take pictures of a ceiling. But the metadata attached to the images suggest they were shot by an Asus-manufactured Nexus 7 in "Google Building 44."

The 1,280 x 960 images, which may have been reduced in size, were uploaded by Google+ user Somit Bh, who appears to have plenty of Google contacts in his Circles.

Google's Nexus S smartphone was unveiled in a similar way two years ago.

An Asus employee confirmed the existence of the 7in tablet earlier in June, but revealed few details other than it was forthcoming. The device is expected to be powered by Nvidia's quad-core Tegra 3 processor, shipping with 1GB of RAM and either a new version of Android Ice Cream Sandwich or the still-unreleased Android 5.0 Jelly Bean.

The Asus Nexus 7 is rumoured to be priced towards the lower end of the market, in the $150 - $250 (£95 - £160) range.