The inspirational New York Times bestseller, Three Cups of Tea, may be rife with inaccuracies, alleges 60 Minutes in a report due to air this Sunday on CBS. The 2006 memoir was co-written by Greg Mortenson, a mountaineering humanitarian who co-founded and directs the Central Asia Institute, a non-profit that’s supposedly built 170 schools in rural Afghanistan and Pakistan. But the CBS newsmagazine is claiming many of the schools the Institute built were either built by someone else, or simply don’t exist.

After attempting to climb K2, an exhausted Mortenson says in his book that he stumbled upon a Pakistani village, and hospitality and warmth he experienced inspired Mortenson to build a school there. Into the Wild author Jon Krakauer is one of Mortenson’s doubters who 60 Minutes will cite in its broadcast Sunday night.

Penguin, Mortenson’s publisher, did not return EW’s requests for comment.