Mass Effect is set to feature a four-player co-op online mode, according to various sources.
Eurogamer reports that the much-rumoured multiplayer feature will include "competitive elements" and "will not compromise" the single-player portion of the game.
A reliable development source has since informed CVG that the Mass Effect 3 multiplayer feature will be built around "original missions made for online", which will be totally unique from the solo campaign.
Our mole added there would "only be a handful" of co-op missions which have been created with the intention of being "played and played again".
Reports have suggested that the online offering will come in the form of a Horde-style mode, but our source was quick to play down the notion.
Bioware's Montreal studio is said to be behind the co-op side, and was seen to be recruiting for "multiplayer" staff last year.
"Mainstream penetration is a major goal for Mass Effect 3 and those high up feel online co-op is the answer they're looking for," our source said. "EA's keen to push the multiplayer side of the game to help spread word of mouth - so it's not just going to rehash stuff from the campaign. It's going all out."
Officially BioWare's refusing to confirm the Mass Effect 3 online antics, but when pressed on the matter last week, co-founder Ray Muzyka told CVG that the studio is "exploring" multiplayer for all of its games.