May 3, 2013 -- Slayer co-founder Jeff Hanneman's death from liver failure on Thursday is still something of a mystery, but that hasn't stopped fans from speculating as to why his liver failed when he was only 49. One of the more dramatic theories making the rounds on Twitter and in the media is that it was a spider bite two years ago that led to an infection and ultimately to his death.

Not so, say experts.

The spider bite was alleged to have happened in 2011. It was then that Hannemen had been sidelined from performing after contracting necrotizing fasciitis, commonly called the "flesh-eating" bacteria.

But doctors say it's unlikely that such a past infection would have directly led to liver failure -- and his assumed spider bite might never have occurred. (Slayer spokeswoman Heidi Robinson-Fitzgerald said the band was not currently releasing more information on Hannemen's health and was consulting with a doctor to determine what could have led to his liver failure.)

Dr. William Schaffner, an infectious disease expert and chair of Preventive Medicine at Vanderbilt University Medical Center, said that in spite of Hannemen's injuries from the infection -- physical therapy and operations on his arm -- the original infection would not have lasted this long.

PHOTOS: In Memoriam: Jeff Hanneman of Slayer Dead at 49

Hannemen first contracted the infection after a friend's hot tub in the Inland Empire region of California. He felt what he thought was a spider bite, although he didn't see the insect. His wound quickly worsened, Hanneman went to seek medical help, and doctors diagnosed him with necrotizing fasciitis. The disease is a bacterial infection that destroys the body's soft tissue.

The effects were so devastating for the guitarist that he was only able to perform with Slayer once before his death, when he played two songs during a 2011 concert.

"He was still working to regain dexterity needed," said Slayer spokeswoman Heidi Robinson-Fitzgerald of Hanneman."If [Slayer] had played slow songs, he could have done it."

Although Hannemen's type of injury led him to believe that the infection was the result of an untreated bite from a brown recluse spider, insect experts say that is unlikely. Brown recluse spiders, also called the violin spider, are found almost exclusively in the Midwest and the South.

Dr. Doug Yanega, senior museum scientist at the Entomology Research Museum at the University of California-Riverside, said virtually all sightings of the brown recluse spider in Southern California were related to someone having accidentally transported the dangerous insect into the area.

Recluse spiders usually avoid humans when people are active, added Yanega. They're more likely to be bitten when they're sleeping and the spider can move without feeling threatened.

"They're named recluses for a reason, they don't come out," said Yanega. "If he was up and about and walking around, it was unlikely to be a spider bite."

Yanega said another possibility is that Hanneman was bitten by a Chilean recluse spider, which has been reported in the Los Angeles area and can cause a similar reaction to that from the brown recluse. But, Yanega said, confirmed reports of people suffering bites from Chilean recluse spiders were also extremely rare.

"The odds are so slim. There are so many other things that cause the same symptoms," said Yanega. "That's one of the most unlikely things it could be."

In 2004 the Entomology Department at Cal-Riverside posted an article on its website describing a wide range of other diseases, which have commonly been mistaken for a brown recluse spider bite including tick bites, diabetic ulcers and lymphoma.

Schaffner Hannemen's infection could have been caused by any number of minor cuts or scratches that allowed bacteria to get below the surface of the skin.

"Any little thing can do it," said Schaffner of necrotizing fasciitis. "It's often an injury that goes unnoticed."

Schaffner said even if the wound was confirmed to be a spider bite, it can be very difficult to discern if the bacteria came from the insect itself or from bacteria entering through an open insect bite.

Hanneman died Thursday morning in a Los Angeles area hospital with his wife, Kathy, by his side. No funeral arrangements have been announced.