Updated

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.

Ban told the council that such statements undermine the U.N. and are an insult to the more than 3,000 people who died.

Susan Rice, the U.S. Ambassador to the U.N. in New York, also said Tuesday she is appalled by Falk's remarks.