Updated at 4:26 p.m. ET
GRANTS PASS, Ore. David Oliver Relin, co-author of the best-selling book "Three Cups of Tea," said in legal filings about a year before his recent suicide that his career suffered from allegations of lies in the story of a humanitarian who built schools in Pakistan and Afghanistan.
Relin committed suicide in the suburban Portland city of Corbett last month, according to the deputy Multnomah County medical examiner, Peter Bellant, late Sunday. He was 49.
Relin died of a blunt force head injury on Nov. 14, Bellant said. He declined to provide other details.
The book, which has sold about 4 million copies since being published in 2006, describes how Greg Mortenson, the other co-author, resolved to build schools for Pakistani villagers who nursed him to health after a failed mountaineering expedition.
The account came under scrutiny last year when CBS' "60 Minutes" and writer Jon Krakauer said it contained numerous falsehoods.
In April, a U.S. district judge rejected a lawsuit by four people who bought the book, dismissing claims that the two authors, the publisher, and a charity conspired to make Mortenson into a false hero to sell books and raise money for an associated charity.
In an August 2011 court filing, Relin attorney Sonia Montalbano said the litigation "has had a negative impact on Relin's livelihood as an author."
In another filing, Montalbano said "Relin takes no position on many of the accusations made by the Plaintiff" but "does stand by the manuscript he wrote."
She pointed out that in an introduction Relin wrote for "Three Cups of Tea," he "fully acknowledged potential inaccuracies." In that introduction, Relin wrote that Mortenson's "fluid sense of time made pinning down the exact sequence of many events in this book almost impossible."
Following allegations that parts of "Three Cups of Tea" were made up, Mortenson denied any wrongdoing, though he has acknowledged some of the events were compressed over different periods of time.
"Three Cups of Tea" was conceived as a way to raise money for and tell the story of Mortenson's Central Asia Institute, which he co-founded in 1996 to build schools in Central Asia.
Montalbano described Relin in court documents as a journalist looking to write his first book when he was approached by a magazine editor Mortenson contacted looking for a writer to tell his story.
Relin then interviewed Mortenson, attended several of his lectures and read previous articles before preparing a book proposal that was bought by Penguin Group. After selling Penguin on the idea, Relin then conducted more interviews with Mortenson and others before writing the manuscript, Montalbano said.
In a 2008 interview with the University of Oregon literary journal Etude, Relin said he had objected to Mortenson being identified as co-author.
"That's been the only negative thing about this whole adventure for me," Relin said.
"It was published that way over my objections," he added.
The publisher released a statement, saying, "All of us at Penguin are saddened to hear of the death of David Oliver Relin. We extend our heartfelt condolences to his family."
Relin was born in Rochester, N.Y.
His second book, "Second Suns, Two Doctors and Their Amazing Quest to Restore Sight and Save Lives," was scheduled to be published in June.
The lawsuit against Mortenson, Relin and Penguin was filed in May 2011 in Montana, where Mortenson lives and the Central Asia Institute is based.
Relin was not involved in a separate investigation by the Montana attorney general into how Mortenson ran the charity.
The investigation led to a settlement in April that called for Mortenson to reimburse the charity nearly $1 million, his removal from a position of financial oversight and an expansion of the board.
The probe and settlement did not deal with the content of "Three Cups of Tea" or Mortenson's sequel, "Stones Into Schools," which Relin did not write.