2:51 PM PT -- Carole is shooting down allegations her missing husband is buried on her property under or inside a septic tank.
CB claims the rumors were started by a disgruntled employee, who was fired 3 years after Don's disappearance.
Carole says she would have looked inside the septic tank to see if he fell in if the theory held any water.
Speaking of water, she also says there wasn't much rain the year Don went missing and doubts he drowned.
Carole says she doesn't recall the septic tank needing to be filled with dirt, and posits the dirt could have been used for something else on the property.
The case of Carole Baskin's disappeared husband, Don Lewis, is going the route of 'Don't F**k with Cats' -- with an online group claiming it's dug up a massive, and crappy, clue about where his body might be.
Jack Smith -- the spokesman now repping Don's family -- tells us he and a group of internet sleuths joined forces earlier this year after the premiere of 'Tiger King' and formed a Facebook group to search for the truth about Don's still-unsolved disappearance in 1997.
Welp, we're told the group believes it discovered a new lead, tied to an existing theory about Don -- namely, that he was allegedly buried on his and Carole's animal sanctuary property under a septic tank system.
According to Jack ... the research team has obtained the actual receipts and permit paperwork for the septic tank's installation. Carole has publicly acknowledged two septic tanks -- one that she claims was installed well before Don's disappearance, and another installed well afterward.
Fox 5 Atlanta
BUT, if you believe what Jack and co. claim these receipts show ... a septic tank system was, in fact, worked on and installed right around the time of Don's disappearance ... 23 years ago this month.
They claim the receipts show a permit to install the septic tank was pulled on August 4, 1997, and that work on such a system was completed by or before the 15th later that same month, with a mound of dirt delivered to Carole's address the day prior.
So, what does that all mean??? According to Don's family and this crack Facebook team of investigators, it points to the possibility that Carole wasn't truthful with her timeline ... and that Don may very well be under the ground, like Joe Exotic himself suggested in the docuseries.
We're told the group will turn this finding and others they claim to have over to the cops, in hopes of cracking the case wide open again.
We've reached out to Carole about the group's new findings ... so far, no word back.