(CNN) As authorities investigate whether a bomb could have been smuggled aboard Metrojet Flight 9268 , CNN has seen private security personnel in Sharm el-Sheikh, Egypt, using handheld bomb detectors that British officials and security experts say just don't work.

Despite tightened security in the resort in the wake of the disaster which claimed 224 lives , CNN witnessed security guards at hotels and shopping centers using "bomb detectors" of a similar design to those banned for export by the British government.

Asked about images of the devices in use in the Red Sea resort where Flight 9268 began, a spokesman for the British Foreign Office said it had raised the issue with Egyptian authorities.

"We will continue to raise our concerns over the use of the devices in question," said the spokesman.

'Magic wand' detectors

The detectors -- consisting of a plastic case with a protruding antenna -- closely resemble the infamous ADE 651 , a fake bomb detector sold throughout the Middle East and other hotspots by a British con man.

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James McCormick was sentenced to 10 years in prison for fraud by a London court in 2013 over the scam, which netted him tens of millions of dollars in sales around the world and funded a luxurious lifestyle.

The device, which contained no working electronic components, was really a novelty golf ball finder with the label removed, British police said.

"These devices contain absolutely nothing inside. There's no laws of science or physics that could make them work," Detective Inspector Edward Heath told CNN in 2013.

Hotel 'working with authorities'

Devices similar in appearance were seen being used by security staff at four different locations in Sharm el-Sheikh: two hotels and two shopping malls. Two different brands of the devices were in use.

Management at a hotel where security staff were photographed using the bomb detectors did not directly answer questions about the devices. The hotel said in a statement Tuesday it was working "closely with the local authorities on security measures employed at our hotels."

"We are deeply saddened by the tragedy last Saturday and continue to monitor the situation closely," read the statement. "We encourage travelers to follow the travel advice of their respective governments and travel authorities."

One of the hotels where the devices were seen also used a bomb-sniffing dog in its security measures. Many hotels in the Egyptian tourist resort have metal detectors in their lobbies, with high-end hotels also using X-ray machines as part of their security protocol.

'They don't work'

Paul Biddiss, a UK-based security consultant who spent 24 years in the British army, examined CNN pictures of security staff using the devices in Sharm el-Sheikh. He said they were typical of the bogus "magic wand" devices and had no value in bomb detection.

"It's a piece of junk," he said. "They don't work. There's no science behind them."

Variations of the devices -- with different casings, all featuring antennas -- have been sold around the world: McCormick's ADE 651; the GT200, which was purchased by the Thai government; the Alpha 6. The British manufacturers of each device have been jailed for fraud in recent years, he said.

There had never been a legitimate bomb detection device that used a similar design, or a working variation of this "technology," he said.

UK export ban

Amid rising concerns about the ADE 651 and the GT200, the British government banned the export of "electrostatically-powered bomb detectors," as the manufacturers described them, to Afghanistan and Iraq in 2010, a spokeswoman for the UK's Department for Business, Innovation and Skills confirmed.

McCormick was later sentenced for fraud in 2013, and the manufacturers of the GT200 and the Alpha 6 followed in his wake.

Biddiss said that the British manufacturers of the bogus devices had sold them widely to government security forces in foreign hot spots.

McCormick's sentencing judge, Richard Hone, noted that one invoice showed his company's sales to Iraq had totaled more than $38 million over nearly three years.

Following the publicity over the products' shortcomings, government forces stopped using them, and they now appear to be making their way into the hands of the private sector, said Biddiss.

"Hotel staff are obviously using them, obviously more for show than anything," he said. "You'd have a better chance of finding a bomb with a water pistol."