The Japanese government believes "there is a high possibility" that Iraq possessed weapons of mass destruction, despite congressional testimony to the contrary given by a former top U.S. arms inspector.

"There's no guarantee that (the WMD) do not exist," Chief Cabinet Secretary Yasuo Fukuda told his regularly scheduled news conference Thursday. "Rather, it is more likely that they do exist. Or, you can think of the possibility that they have been hidden somewhere in some way."

On Wednesday, David Kay, who led the Iraq Survey Group in its fruitless seven-month search for WMD, told the U.S. Senate Armed Services Committee: "I believe that the effort that has been directed to this point has been sufficiently intense that it is highly unlikely that there were large stockpiles of deployed militarized chemical and biological weapons there."

Kay lambasted U.S. intelligence activities that led to the questionable WMD reports. The information regarding the alleged weapons stockpiles in Iraq before the war was wrong, he said.

Fukuda challenged the credibility of Kay's statements.

"He was once in charge of (the investigation) but that is no longer the case," he said. "You have to consider what his account is based on."

When the U.S.-led war on Iraq began in March, Prime Minister Junichiro Koizumi voiced staunch support, despite criticism that the action was in violation of international law.

One of Koizumi's reasons for backing the war was concern over Iraq's alleged WMD.

"It is like being betrayed and bitten by a pet dog you trusted," a Foreign Ministry official said Thursday in reference to Kay's remarks.