Authorities believe Russell Armstrong was dead for more than 24 hours before his body was discovered ... TMZ has learned.
Sources tell TMZ ... the last known contact anyone had with Russell was last Saturday, when he was on the phone with a friend.
As we first reported, Russell was a no-show for a meeting with Taylor on Monday afternoon, which sounded alarm bells and began hours of frantic searching.
Russell's body was discovered at 8:08 PM Monday.
And, sources tell TMZ, Russell's body was found hanging from a wooden beam in the bedroom, with an orange extension cord around his neck.