THAT'S SAD! BRITNEY MURPHY'S HUSBAND SIMON MONJACK DIES OF A POSSIBLE OD JUST 5 MONTHS AFTER HER!

Law enforcement sources tells TMZ there are signs Simon Monjack may have died from an accidental overdose of prescription drugs.

One well-placed source says, "There were a number of pill bottles on the nightstand in the bedroom, and some were empty."

There is, obviously, an eerie similarity to the death of Monjack's wife, Brittany Murphy, just five months ago. In her case an array of prescription drugs were found on the nightstand of the same bedroom where Monjack died. Many of the drugs on Simon's nightstand were the same as the ones found after Brittany died.

One law enforcement source says the two causes of death that seem most plausible at the moment are "natural" and "accidental drug overdose."

Monjack told TMZ recently he had suffered a heart attack during the incident last November when he had a medical emergency aboard an airplane.

Brittany's mother, Sharon Murphy, discovered Monjack's body last night. She is also the one who found her daughter, Brittany, unconscious and on the floor of the bathroom five months earlier.

UPDATE: TMZ has learned Simon was scheduled to have bypass surgery in September.