A policeman in Baghdad knows the bomb detector he uses is fake, and will do virtually nothing to save anyone's life, but he has his orders.

"If I were given a mop and told that it detects bombs in cars, I would still do it without any hesitation," he told AFP, asking not to be identified.

"The device is a 100-percent failure and we know that, but it is imposed on us; we cannot disobey direct orders," he added.

James McCormick, a British businessman, made an estimated 50 million pounds ($76 million/59 million euros) selling the "bomb detectors," said to be based on a novelty golf ball finder, to Iraq and other countries.

He was sentenced on Thursday to 10 years in jail for fraud.

But despite the sentencing and overwhelming evidence that the devices are worthless, the Iraqi government has not taken them out of circulation.

Relying on bomb detectors that do not work is an especially grave issue in Iraq, where violence is a major problem and bombings by militants are common.

April was the bloodiest month for the country in almost five years, according to the United Nations.

Most Iraqis familiar with the devices, made of black plastic with a pistol-style grip and a small silver antenna, do not hold them in high regard.

"The issue of the devices that the government imported... is like that person who lies to himself and then believes his own lies," said Yassir al-Khattab, who owns an electronics shop in central Baghdad.

"They know well that the devices do not work, but they use them as a psychological factor, and they will continue to use them because... they do not have anything else to show in front of the public," he said.

Army Captain Saleh Mohammed said security forces do not trust the devices.

"The soldier holding the device is himself not confident in it, but it is imposed on him," Mohammed said.

"We already told the officials that the device is not working properly but they wanted to show the people that they did something," he said.

Mohammed also had sharp words for Britain for allowing the devices to be exported in the first place.

"The British government must be held responsible for all the explosions that happened," Mohammed said.

It "is an advanced country and has quality control," he said, asking how officials there could have not known the "detectors" were being marketed.

Did they not "know that these devices do not work as they examined them? Didn't they take taxes for exporting them?"

British firm Advanced Tactical Security & Communications Ltd. (ATSC) made a number of fantastical claims about the devices.

It said they could pick up substances ranging from explosives to ivory at up to 1,000 metres (3,280 feet) on the ground or 3,000 metres (9,842 feet) from the air, using credit card-sized "sensor cards".

The reality, however, proved rather different.

Interior ministry inspector general Aqil al-Turaihi said a report from the security command responsible for Baghdad found that in one area, the device, even in concert with other security measures, prevented only 19 percent of bombing attacks.

"I believe that this device contributed, whether intentionally or unintentionally... to the shedding of Iraqi blood," he said.

McCormick was found guilty of three counts of fraud at the Old Bailey court in London last week.

Judge Richard Hone, who handed down the sentence on Thursday, said he was "wholly satisfied that your fraudulent conduct in selling so many useless devices... promoted a false sense of security and in all probability materially contributed to causing death and injury to innocent individuals."

Deputy Interior Minister Adnan al-Assadi told AFP the devices will be replaced, but did not say with what or when.

Until then, policemen and soldiers will continue holding the devices parallel to cars at checkpoints, watching for the silver antenna to swing toward one, indicating a threat.

But that is something they will never do, except by chance.