Matt Schlapp, chair of the American Conservative Union, the group that organizes CPAC, said in a statement that the decision was "due to the revelation of an offensive video in the past 24 hours condoning pedophilia."
Yiannopoulos -- whose scheduled appearance last month at the University of California Berkeley sparked riots and was cancelled -- responded to the allegation that he appeared to be defending pedophilia in a post on Facebook, saying: "I do not support pedophilia. Period. It is a vile and disgusting crime, perhaps the very worst. There are selectively edited videos doing the rounds, as part of a co-ordinated effort to discredit me from establishment Republicans, that suggest I am soft on the subject."
In the statement disinviting Yiannapoulos, Schlapp called his defense "insufficient," and called on him to more fully address the issues raised by his comments.
Some conservatives expressed immediate outrage at the invitation to Yiannopoulos, who's been a staunch supporter of President Trump but has alienated many on the right with his ultra-conservative views on issues such as immigration and race relations.
CPAC is an annual gathering for the nation's top conservative thinkers. It is scheduled to take place later this week in National Harbor, Maryland. Confirmed speakers include Vice President Mike Pence and White House Chief Strategist Steve Bannon.