The U.N. chief says a U.N. appointed expert on Palestinian rights made preposterous remarks when he alleged an apparent cover-up by U.S. authorities involving the Sept. 11 terror attacks.

Secretary-General Ban Ki-moon condemned Tuesday what he called the inflammatory rhetoric of Richard Falk, a U.N. special rapporteur appointed by the U.N.'s Human Rights Council in Geneva.

Falk suggested the cover-up in a blog post this month and criticized mainstream media for being unwilling to look into doubts about the attacks in New York and Washington....