Republican accusations that a nonprofit Muslim advocacy group placed “spies” on key House national security committees have spurred a death threat, the group said.

The spokesman for the Council on American Islamic Relations (CAIR) said in an e-mail that he had received a faxed death threat on Thursday following accusations by four GOP members of the Congressional Anti-Terrorism Caucus.

The fax had a picture of a gallows and stated that spokesman Ibrahim Hooper would be hanged “for treason.”

“[CAIR’s] national communications director today received a faxed death threat that stated: 'Muslim Neanderthal Dougie Hooper (AKA Ibrahim Hooper) will be soon hanged for treason against the United States’,” Hooper wrote in an e-mail.

CAIR has informed the FBI of the threat, he said.

Reps. Sue Myrick (R-N.C.), John Shadegg (R-Ariz.), Paul Broun (R-Ga.) and Trent Franks (R-Ariz.), citing the book "Muslim Mafia: Inside the Secret Underworld that’s Conspiring to Islamize America," called on Wednesday for the House sergeant at arms to investigate whether CAIR had been successful in placing interns on key panels.

The lawmakers are specifically focused on the House Homeland Security Committee, Intelligence Committee and Judiciary Committee.

The Republicans also accused CAIR of illegal lobbying practices.

Hooper said the claims were false and that the lawmakers were acting in connection with “extremists.”

“It is troubling that right-wing elected officials would serve as publicity agents for extremists who seek to bar an American minority from exercising its constitutionally protected rights,” he said.

“We applaud those who stand up for the right of all Americans to participate fully in our nation’s political system.”

House Judiciary Committee Chairman John Conyers (D-Mich.) and Rep. Loretta Sanchez (D-Calif.) came to the defense of CAIR, saying that Muslim-American interns on Capitol Hill should not have their patriotism questioned.

“Numerous Muslim-American interns have served the House ably and they deserve our appreciation and respect, not attacks on their character or patriotism,” said Conyers in a statement.

Hooper also said that CAIR’s offices in Washington, D.C., Detroit, and Northern and Southern California have all received obscene phone calls in the past 24 hours.