David Oliver Relin, who co-authored of the best-selling memoir "Three Cups of Tea" and declined to respond to allegations that it was partially fabricated, commited suicide last month, The Associated Press reported.
He died in Corbett, Ore., near Portland, on Nov. 14. A medical examiner told the AP that Relin, 49, 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, a 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 contained numerous inaccuracies and fabrications that made Mortenson appear more heroic.
"60 Minutes" and Krakauer suggested Mortenson used his charity and book sales to bankroll an extravagant lifestyle for himself, while the schools he helped build remained threadbare or unused.
Mortenson denied any wrongdoing, though he admitted that he compressed the timeline of events in the book. Relin did not publicly comment.
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.