A man who was declared dead by three doctors was actually still alive, which doctors discovered only when he began snoring on the autopsy table, according to news reports.

The man, a 29-year-old had been incarcerated in a jail. He was found unconscious in his cell on Sunday, and was believed to be dead.

Three forensic doctors allegedly examined him and certified his death.

Snores before autopsy

But 4 hours later, right before his autopsy, he was heard making noises on the autopsy table, and was found to still be alive.

This discovery was not a moment too soon —  his body even had the marks painted on it to guide the autopsy, a family member said.

Determining whether someone is dead or alive might sound simple enough, but there are not universal guidelines for exactly when doctors should pronounce someone dead.

"You're dead when a doctor says you're dead," Dr. James Bernat, a neurologist at Dartmouth College's Geisel School of Medicine in New Hampshire says.

Broadly speaking, a person may be declared dead when one of two things happens: Their heart stops beating and doesn't start again, or they are "braindead."

Man resurrects in Kenya

Similar incidences have been reported in Kenya.

A man in Naivasha apparently rose from the dead. Paul Mutora had been confirmed dead in Naivasha District Hospital only to wake up 15 hours later among the dead bodies in the mortuary.

Mortuary staff fled after the 24-year-old man 'resurrected' and operations in the busy facility were paralyzed for hours.