Christopher Dorner Presumed DEAD -- After Gun Battle with Cops

8:20 PM -- The LAPD held a news conference and said no body has been pulled out of the scorched cabin yet ... as it is still too hot to enter.

Law enforcement sources directly connected to the case tell TMZ a body was found inside a Big Bear cabin, and they are all but certain it is Christopher Dorner -- who earlier engaged police in a gunfight before the cabin went up in flames.

We're told positive identification may take a while because the body was badly burned, but our sources are convinced they have their man.

Cops had cornered Dorner in the remote cabin ... after reports came in that he robbed a nearby home, tied up the couple living inside and fled in a white Dodge pickup truck.

A state Fish & Game ranger fired on the vehicle, and cops closed in soon after -- resulting in a violent standoff ... during which tons of shots were fired, hitting two San Bernardino County deputies ... one of whom died at the hospital.

At this point, it's unclear how exactly Dorner died. Cops reportedly heard a single gunshot around the time the cabin ignited ... indicating Dorner might have shot himself.

Dorner was accused of murdering three people -- including one police officer -- in shootings that took place on February 3rd and February 7th in California. Two other police officers were injured in the shootings.

Cops believe Dorner -- a former LAPD officer who was dismissed in 2008 -- posted a rambling manifesto on his Facebook page ... in which he declared "unconventional and asymmetric warfare" on the LAPD and their families.