U.S. Defense Secretary Leon Panetta
U.S. Defense Secretary Leon PanettaU.S. Defense Secretary Leon Panetta

U.S. national security officials consider Israel to be, at times, "a frustrating ally and a genuine counterintelligence threat," an Associated Press investigative report reveals.

The report quotes U.S. officials' claims that Israeli agents have carried out intrusions into the homes of CIA Israel station chiefs in the past decade. In addition, it says, "Israel has been implicated in U.S. criminal espionage cases and disciplinary proceedings against CIA officers and blamed in the presumed death of an important spy in Syria for the CIA during the administration of President George W. Bush."

As a matter of fact, the CIA considers Israel "its No. 1 counterintelligence threat" in the Middle East, according to current and former officials quoted by AP.

A text message Saturday from the office of Israeli Prime Minister Binyamin Netanyahu called the report "false."

An Israeli spokesman in Washington told AP that "Israel's intelligence and security agencies maintain close, broad and continuous cooperation with their U.S. counterparts. They are our partners in confronting many mutual challenges. Any suggestion otherwise is baseless and contrary to the spirit and practice of the security cooperation between our two countries."