Sony fansite PlayStation Lifestyle claims to have blown the lid on the next game from Team ICO, codenamed Project Trico.
In a video lasting nearly four minutes, we see a boy and a giant bird-rat in very ICO-esque environments, apparently co-operating on some sort of unspoken shared quest.
The visual style is reminiscent of ICO, and so are individual details like the boy's clothing. The movement of the bird-rat thing is very organic, almost feline, calling to mind the developer's previous work on Shadow of the Colossus.
Sony has never previously confirmed details about Trico, but Team ICO's disciples will note with delight that the chain binding the bird-rat at the start of the trailer is the same as the one that appeared in a Team ICO job advert at the beginning of last year.
Following the trailer's release, posters on the NeoGAF forums have claimed that the video is internal test footage shown around Sony over a year ago.
From that, we can infer that the trailer's leak is not a portent of what Sony will do at E3 in two weeks' time, although the fact that details are in the public domain may accelerate any plans.
We're waiting to hear back from Sony Europe, but the platform holder told GameSpot: "We've made no announcement of anything called 'Project Trico.'"
Update: Sony Europe said it had no comment.