A sound designer with Sony Computer Entertainment America listed work on both the PlayStation 3 and Vita versions of the game through his LinkedIn online CV.
The listing seems to confirm rumours of a Vita port, which began last week when the game's director suggested that it might be in development for an E3 reveal.
Without an official announcement from Sony, it is unknown whether the Vita version will release simultaneously with its PS3 counterpart or if it will arrive some time afterward.
PlayStation All-Stars Battle Royale is a mascot-filled brawler similar to Nintendo's Super Smash Bros Melee. Rumours of its existence intensified after a domain name was registered by Sony.
Confirmed characters include Fat Princess, Sly Cooper, Colonel Radec from Killzone, Parappa the Rapper, Kratos from God of War and Sweet Tooth from Twisted Metal.
Additional characters Solid Snake, Nathan Drake, Cole MacGrath and PlayStation spokesman Kevin Butler have also been hinted at.
It will offer single and multiplayer modes, including support for up to four players locally, as well as a number of online tournament options.
The game has been in development for the past two years, with a scheduled release for later this year.
Watch a trailer for PlayStation All-Stars Battle Royale below: