Preliminary work on PlayStation 4 games has begun at several internal Sony studios, Develop understands.

A trusted source connected to the matter has told Develop that various game projects are at very early stages, though didn’t reveal which of Sony’s sixteen first-party studios had been delegated the work.

Few in the games business expect a new PlayStation to launch before 2014 – the next few Christmases will likely see Sony marketing software for PS3, Move and its new Vita handheld.

A Sony spokesperson has declined to comment.

The discovery comes as rival platform holder Microsoft continues work on its next-generation system. Develop has published data from various sources that points to a Christmas 2013 release for the so-called ‘Xbox Next’.

It is a company convention at Sony to remain constantly engaged in R&D work on future platforms – in fact PS Vita development began soon after the release of the PSP in 2005. But Develop has been told that several SCE studios now have teams working on PS4 game concepts that could jump into full production if given the green light.

Many developers believe PlayStation 3, which first launched five years ago and has gone on to sell more than fifty million units, remains a high-end machine.

In a new interview with Develop, Epic president Mike Capps said it would be a “very tall order” to build commercial hardware that is a generational leap forward.

“I mean, PS3 is still very bad-ass,” he said.

What is clear is that Sony is some distance from finalising the technology behind its next generation console, and any early input from internal game studios will be a relief to the development industry.

Last year, Worldwide Studios (WWS) boss Shuhei Yoshida said Sony has learnt from past mistakes and is now asking game developers to help shape future technology.

“We wanted developers in meetings at the very beginning of concepting new hardware,” he told Develop.

In February, SCE chairman Kaz Hirai said Sony was “not deliberating on PS4”.

The company has built a strategy to support consoles with new games for about ten years, and the experienced executive pointed out that PS3 has not even reached its fifth year yet.

In May, Sony's chief financial officer Masaru Kato explained to investors that "future platform" development work has caused a spike in R&D costs.