It's the bestseller sweeping the nation with more than two million copies sold. Proof of Heaven is the story of a neurosurgeon's near-death experience and what he says was his journey to heaven.
But now, a writer is raising questions about Dr. Eben Alexander’s "proof."
"The story that he tells in his book, does not hold up to scrutiny," said Luke Dittrich.
Dr. Alexander once preferred the scientific over the spiritual. That changed when he almost died four years ago.
On Fox News, Dr. Alexander once said, "Beauty, flowers, butterflies, this little girl who was my guardian angel soaring above."
He was in a coma, battling bacterial meningitis when he says he saw the afterlife and then came back to life.
When he was once on Oprah she asked, "What we all want to know is, did you see God?"
Alexander said, "Yes, there was this brilliant orb of light. It was brighter than a million suns."
His story has turned skeptics into believers and brought him worldwide fame.
But, Esquire contributing editor Luke Dittrich said he found a "series of factual omissions and inconsistencies that call significant parts of Dr. Alexander's story into question."
Take the moment when Alexander wrote that he was in the hospital and yelled out, "God, help me!"
Dittrich told INSIDE EDITION, "When I spoke to the emergency physician who was treating him, I asked her if she remembered that particular episode. She said, 'No,' she did not, and further that he had been intubated, which would prevent him from speaking at all."
The Esquire writer also questions Alexander’s description of the weather the day he woke up from his week-long coma. After six days of rain, Alexander writes that "a perfect rainbow" appeared in the sky.
Dittrich said, "I called the meteorologist in charge and when I asked him whether or not on that final day he saw the conditions that would allow for, you know, a rainbow. He told me, 'No.'"
INSIDE EDITION's Paul Boyd asked, "Some people are going to hear you attacking his vision of a rainbow and say, 'Come on, you are not even giving this guy his rainbow moment here?'"
Dittrich replied, "I took what I could from the book that was verifiable and tried to verify it."
A defiant Dr. Eben Alexander just released this statement: "I stand by every word in this book and have made its message the purpose of my life. Esquire's cynical article distorts the facts of my 25-year career as a neurosurgeon and is a textbook example of how unsupported assertions and cherry-picked information can be assembled at the expense of the truth."
Boyd asked Dittrich, "Dr. Alexander says your article is 'cynical' and 'distorts the truth.' Would you like to respond to that?"
"Yeah, I would. When somebody markets a non-fiction book as a work of non-fiction, when he calls it Proof of Heaven, I think it is not cynical at all to look at that book hard, under the light."