Game developer Valve is still keeping silent about the fate of its popular shooter series "Left 4 Dead," despite numerous leaks pointing towards a possible sequel.

A lot of speculations about a possible "Left 4 Dead 3" title have been circulating for quite a while now, and this is pretty much expected. The last "Left 4 Dead" title, "Left 4 Dead 2," was released almost seven years ago, and fans are now more than ready for the next title to drop.

Despite Valve's silence regarding the matter, there were a lot of clues spotted by eagle-eyed "Left 4 Dead" fans, including a screenshot that was speculated as a deliberate tease from the developer.

A folder named "left4dead3" is clearly seen on one of the screenshots. It was since taken down and replaced by an "obviously photoshopped" image, but the original one was already screencaptured and posted on the ValveTime forums.

"From the pessimist's perspective, this was just a mistake," ValveTime forum user Smash wrote. "But it's too convenient that the folder viewport was scrolled exactly so that left4dead3 was shown first."

Another proof was provided by a group of "DOTA 2" Redditors while touring around the Valve office. One of them took this photo, and if zoomed in, shows multiple references to "Left 4 Dead 3."

Yet another spot of information was posted on the ValveTime forums, revealing the existence of a 68-member mailing group for a project titled "Left 4 Dead 3."

No further news has emerged from either Valve or anywhere else, for that matter, which led to other fans wondering if the game is even in development in the first place.

Fans of Valve's franchises would know that the developer has slight issues with game number three. Up until today, players are still waiting for the third sequel for two of Valve's popular games, "Half-Life" and "Portal."

"Left 4 Dead 2" was originally launched for PC and Xbox 360 in 2009, followed by a Mac port in 2010 and Linux port in 2013.