The devices are reportedly being used by security guards at a number of hotels in the popular tourist resort, in the wake of the Russian plane crash that killed all 224 people on board.
The “wand-like aerial” attached to a box was waved over cars and luggage, The Sun reported.
Britain’s foreign office said it will continue to raise concerns about the devices.
A spokeswoman said: “Across the resort, airport style scanners, sniffer dogs, body searches, metal detectors, private security, police, and CCTV are being used to keep tourists safe.
“We will continue to raise our concerns over the use of the devices in question.
“While we have updated our advice on travelling to Sharm el-Sheik by air, we have not changed the threat level for the resort.”
The detection devices used at the hotels appear to be based on those which came to prominence in recent years when a number of people in the UK were convicted in connection with fake bomb detectors, security analyst Paul Beaver said.
He said: “IS operatives planning an attack would be wise to them [the devices] and would know instantly that they offer no protection at checkpoints.
“It’s doubly disturbing that these devices seem to be a version of the gadget exposed as a crude con trick two years ago.”
In 2013, conman James McCormick from Somerset was jailed for 10 years after being found guilty of three offences of fraud, having sold fake bomb detectors to Iraq.
The same year, Gary Bolton from Kent was jailed for seven years over the sale of more than 1,000 useless detectors which he claimed could track down bombs, drugs, ivory, and money.
Meanwhile, all Britons stranded in Sharm el-Sheikh should be home by the end of this week, according to British foreign secretary Philip Hammond.
Thousands of holidaymakers remain in the popular Egyptian resort, held up after the decision to suspend routine air links and increase security measures in the wake of the crash that killed all 224 people on board.
A total of 2,301 passengers returned to the UK on Monday on 11 flights from the Egyptian resort.
Asked during a press conference in Washington DC about the delays for Britons trying to get back to the UK compared to other countries, Hammond said the government had insisted on “some very significant increased security requirements” to ensure the safety of passengers.
Hammond said they are happy with how the process is going. Investigators are understood to be 90% sure a noise picked up by the cockpit voice recorder in the final seconds of the flight was the sound of an explosion caused by a bomb.