Series regular Ada Wong will appear in Resident Evil 6 in a fourth campaign, files uncovered from the newly released demo appear to suggest.

The files - spotted on NeoGAF - reveal that the grappling hook Ada used in Resident Evil 4 will return in Resi 6, and she will be joined by an unnamed "helper". Character data for Carla - seen in the E3 trailer - has also been found.

Could Ada be the mystery character found on the cover of the Resident Evil 6 Premium Edition?

Ada would join confirmed campaigns featuring Leon S Kennedy, Chris Redfield and Jake Muller.

- Play as Leon S. Kennedy alongside Helena Harper and explore the dark confines of the Ivy University campus and the zombies that fill its hallways.

- Select Chris Redfield's mission and head to China for an intense encounter against the deadly J'avo with BSAA colleague Piers Nivans on the rooftops of Lanshiang.

- The third mission shifts the action to the war-torn Eastern European state of Edonia and sees Jake Muller and Sherry Berkin trying to escape the relentless pursuit of the Ustanak, one of the new B.O.W.'s being introduced in Resident Evil 6.

Resident Evil 6 is scheduled for release on October 2, 2012 for Xbox 360 and PS3. A PC version will follow.