Alvarez had been working at the Jackson family compound in Encino since the singer died last June.
Alberto Alvarez is the bodyguard who called 911 from Jackson's house. Last week it was reported that Alvarez told LAPD detectives ... that before paramedics arrived on scene Dr. Murray asked him to put bottles of Propofol in a bag.
Alvarez -- who is sometimes referred to as Jackson's "logistics director" -- did not tell detectives about the alleged cover-up the day Jackson died, but rather two months later. The story about the alleged cover-up broke last Monday.
As for why Alvarez was fired, the Jackson family isn't talking.