Three Cups of Tea author Greg Mortenson poses with schoolchildren in Wakhan, northeastern Afghanistan, in an undated photograph released March 11, 2009

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Every year, the University of Louisville gives out five $100,000 Grawemeyer Awards. Most of the recipients aren't celebrities — mainly academics outstanding in their fields of expertise. Mikhail Gorbachev, who won one in 1994, was a rare awardee who was also a global star. This time around, however, a faculty member nominated a famous name and, after the candidacy was very well received in the selection process, the university announced on April 14 that Greg Mortenson, author of Three Cups of Tea, was a winner of the 2011 Grawemeyer education prize.

Two days later, however, the school, like the rest of the country, learned of an exposé by CBS's 60 Minutes that alleged that some of the most dramatic episodes in the best-selling book and its popular sequel were inaccurate, if not largely fabricated. Moreover, serious questions have been raised over the way Mortenson has run his nonprofit Central Asian Institute (CAI) and the way it pursues its objective of building schools and educating girls in Afghanistan and Pakistan. (See "Why Three Cups of Tea Are Not Enough.")

The university has not yet decided whether to rescind the award, says Allan Dittmer, executive director of the awards, which are named for an alumnus, H. Charles Grawemeyer, who endowed the honors. Mortenson, a Nobel Peace Prize nominee for the past couple of years, remains a very popular figure among the thousands who have contributed to the CAI and to his Pennies for Peace campaign, which encouraged American schoolchildren to contribute loose change toward the author's Afghan and Pakistani goals. President Obama gave $100,000 from his own 2008 Nobel Peace Prize award to the CAI. "A bazillion questions are surfacing, and I'm guessing those will be looked into very carefully," Dittmer told TIME. "We'll wait to see if he's vindicated, and if not we may have to make a tough decision."

There are numerous allegations against Mortenson. Beyond the 60 Minutes investigation that aired on April 17, they are detailed and documented by another best-selling author, Jon Krakauer (Into Thin Air), in an e-book published on April 18 by Byliner Originals (a company owned by John Tayman, the editor of TIME.com's Techland). Among several claims: that Mortenson conflated two towns in the Pakistani-ruled sector of Kashmir and reneged on a promise to the initial town he visited to confer on it the first school he built; that Mortenson transformed what was a warm, leisurely visit with frontier tribesmen in Pakistan into his kidnapping by Taliban, even though there were no Taliban in the area at the time; and being such an accountant's nightmare that internal auditors were afraid he would be liable for up to $23 million in back taxes for "excessive benefits" taken out of CAI funds. (See Afghanistan's graffiti wars.)

On April 18, Mortenson responded to most of the charges in an interview that ran on the website of Outside magazine. He admitted to "omissions and compressions" in his first book but denied Krakauer and CBS's claim that he did not get to the town at the center of the narrative until a year after the events he described. He said there were villagers who could corroborate his account but argued that the residents of the region find "Westerners' emphasis on time confusing." Mortenson also insisted that he was kidnapped, though he allowed that his abductors did not call themselves Taliban. As for the allegations of using the CAI as a virtual ATM, he says that consultants have told him "basically we've done nothing wrong" and that "as much as it would be great to separate everything, we're all intricately woven ... I'm really the only reason CAI can exist right now."

(Additional points of contention: one of Krakauer's sources is a self-confessed [though penitent] embezzler who ran Mortenson's operations in Pakistan; a minor source, as Krakauer makes clear in a note, is a con man and fugitive from the law who passed a false rumor that he had kidnapped Mortenson in order to extort money from his tribal kin who were the American's hosts.)

As it was, the CBS and Krakauer investigations were reaching a crux just as the University of Louisville was about to announce that Mortenson had won the $100,000 prize. 60 Minutes first reached Mortenson's wife on March 30 and the next day got in touch with his staff. But Mortenson claims he never directly received the e-mail queries the show's Steve Kroft told him he had sent. (Kroft would also attempt to ambush interview Mortenson on April 14 at an Atlanta event, to no avail.) As for Krakauer, he first requested an interview with Mortenson on April 13 and both sides agreed to an April 16 meeting. But Mortenson begged off for health reasons and also refused to be audiotaped. He told Outside, "Once I realized how deep and dirty this whole thing was, I realized I couldn't trust him enough to meet him in the middle of a field without any clothes on." (See the 100 best TV shows.)

Louisville knew early on that Mortenson could not make the official April 13 awards dinner but had a terrible time trying to get him to commit to an alternate date. "It was like trying to get in touch with a CEO," Bill Bush, who oversees the Grawemeyer Award in Education, told TIME. "He has layers of people. I never had the opportunity to talk to him — I was only talking to his staff." Only about a week before the dinner did Mortenson's office return a signed agreement that committed him to a requisite appearance in Louisville to accept the award — in September. (The school could only announce the award on the 14th after the university trustees signed off on the deal.) Dittmer told TIME that Mortenson's staff "gave no indication at all of any problems" when they returned the contract. "The first anyone here was aware of an issue was on Saturday when they ran a 60 Minutes preview. It's alarming to those of us who have worked on this for years." The Grawemeyer staff has tried to contact Mortenson since the story broke. "When you do, you don't get very far," Bush says.

John Ferré, a Louisville professor of communications who has helped judge previous Grawemeyer Awards, says the university is a victim of unfortunate timing. "You do everything you can to ensure you have a powerful idea that we want to champion, which is what the awards are for," he says. "By the time it gets to the award, you assume the facts have been checked. The university, in my mind, is behaving honorably. We give a tremendous series of prizes, and it's possible this one was mistaken. It's also possible this one is not mistaken. I don't think the jury is in yet."

But one person can claim that she spoke forcefully against Mortenson's selection as the winner. "Greg's story took the vast majority of favorable opinions," Tori Murden McClure, a member of the Grawemeyer education committee, told TIME. "I spoke in favor of Linda Darling-Hammond, a professor of education at Stanford, whose research I found to be far more extensive and compelling. A faculty member swung a little in my direction, but both of us conceded to a clear majority." The current president of Spalding University in downtown Louisville, McClure says, "I had no basis in fact for having the heebie-jeebies about him. Greg's done lot of good. He doesn't have to embellish with stories of derring-do that didn't happen. Meanwhile, there was a fabulous book about education in America, and the committee wouldn't look at it because you have this alleged superhero."

— With reporting by Howard Chua-Eoan / New York City

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