The poster, which appeared on the website of CAIR's California chapter, features a sinister looking FBI agent with the headlines, "Build a Wall of Resistance," and "Don't Talk to the FBI."
"I think it's subject to misinterpretation," spokesman Ibrahim Hooper told Fox News Radio. "We decided out of extreme caution to take it down."
The poster was promoting a conference called, "FBI Raids and Grand Jury Subpoenas: Know Your Rights and Defend Our Communities." The keynote speaker is Hatem Abudayyeh, identified by CAIR as an activist and Palestinian community leader whose home was allegedly raided by federal agents in September.
Hooper conceded the poster "crosses the line" but refused to renounce the artwork and blamed critics for fomenting what he called a manufactured controversy.
"The entire American-Muslim community is under the microscope right now with a cottage industry of Muslim bashers," he said. "We're used to this kind of attack by the Islamophobic hate machine and in this case there is some justification in terms of the possibility of misinterpretation of this poster."
Hooper said CAIR is just one of many co-sponsors of the event and he had no idea who was responsible for the artwork. Hooper said he was unable to provide a list of the other co-sponsors.
An FBI spokesperson told Fox News Radio they were aware of the poster but would not comment.
However, former FBI assistant director Bill Gavin told Fox News Radio the poster is sending the wrong message to the Muslim community.
"It sends out a real negative attitude to the Islamic community of what the FBI is really all about," Gavin said. "This is just a propaganda tool to try and thwart an active investigation into criminal acts by a would-be terrorist group."
"Why wouldn't you talk to the FBI," Gavin wondered. "If in fact there is something being done to destroy the image of Islam in the United States, then it should be stopped. We should put a positive face on Islam - not Islamic extremists."
As for the content of the conference, Hooper said if anything negative is said about the FBI, it won't come from their group.
"We have a consistent policy of positive and constructive engagement with law enforcement officials," he said.