“I don’t care about Sandia or the Department of Justice or any of them,” General Jabiri said. “I know more about this issue than the Americans do. In fact, I know more about bombs than anyone in the world.”

He attributed the decrease in bombings in Baghdad since 2007 to the use of the wands at checkpoints. American military officials credit the surge in American forces, as well as the Awakening movement, in which Iraqi insurgents turned against Al Qaeda in Mesopotamia, for the decrease.

Image The sensor device, known as the ADE 651, from $16,500 to $60,000 each. Iraq has bought more than 1,500 of the devices. Credit... Johan Spanner for The New York Times

Aqeel al-Turaihi, the inspector general for the Ministry of the Interior, reported that the ministry bought 800 of the devices from a company called ATSC (UK) Ltd. for $32 million in 2008, and an unspecified larger quantity for $53 million. Mr. Turaihi said Iraqi officials paid up to $60,000 apiece, when the wands could be purchased for as little as $18,500. He said he had begun an investigation into the no-bid contracts with ATSC.

Jim McCormick, the head of ATSC, based in London, did not return calls for comment.

The Baghdad Operations Command announced Tuesday that it had purchased an additional 100 detection devices, but General Rowe said five to eight bomb-sniffing dogs could be purchased for $60,000, with provable results.

Checking cars with dogs, however, is a slow process, whereas the wands take only a few seconds per vehicle. “Can you imagine dogs at all 400 checkpoints in Baghdad?” General Jabiri said. “The city would be a zoo.”

Speed is not the only issue. Colonel Bidlack said, “When they say they are selling you something that will save your son or daughter on a patrol, they’ve crossed an insupportable line into moral depravity.”