David Oliver Relin, the co-author of the best-selling "Three Cups of Tea" that was criticized for factual fabrications, commited suicide in Oregon earlier this month.
The 49-year-old died in Corbett, near Portland, on Nov. 14, the Associated Press reported Sunday night.
A medical examiner told the AP that Relin died of a blunt force head injury, but did not provide other details.
Relin wrote "Three Cups of Tea" as a memoir with mountain climber-turned-humanitarian Greg Mortenson, the nonprofit director who started building schools in Pakistan and Afghanistan.
But the book drew criticism last year when "60 Minutes" and author Jon Krakauer alleged that it there were numerous factual inaccuracies and fabrications that made Mortenson appear more heroic.
The reports also depicted Mortenson as using his charity and book sales to bankroll an extravagant lifestyle for himself, while the schools he raised money to build remained threadbare or unused.
Mortenson denied any wrongdoing, though he admitted that he compressed the timeline of events in the book. Relin had not publicly commented on the allegations.
Relin, who was born in Minnesota, had a long career as a journalist before co-writing the book. He won more than 40 national magazine awards and served as a contributing editor to Parade and Skiing Magazine.