Commercial detectors intended to help domestic abuse victims find hidden spying devices may actually give them a false sense of security, a study has found.

The consumer detection tools claim to identify hidden cameras, microphones or trackers through methods such as signal-strength readings, infrared lens detection and scanning for wifi or Bluetooth devices.

However, researchers at University College London’s computer science department found that many detectors fail to adequately help users identify hidden surveillance devices, giving them a false sense of security.

“There’s quite a great disparity in the capabilities of the [spying] devices themselves and the tools that are available for detecting them,” said the lead author, Akhil Polamarasetty.

The researchers said that if the detectors failed to find surveillance devices it meant victims continued to be spied on in their homes unaware.

The researchers identified approximately 1,000 covert surveillance products and 500 detection tools sold in the UK through mainstream online platforms, such as Amazon, AliExpress and eBay.

Hidden surveillance devices included small cameras or microphones concealed inside everyday household items such as USB chargers, plush toys and clocks.

Often marketed as home security or pet tracking tools, the researchers and campaigners said the devices could be misused for spying and abuse.

“These devices are so small, it doesn’t actually make sense for them to be used for home security purposes,” said Polamarasetty. “[They’re] essentially designed for spying on people.”

The researchers asked 34 study participants to search for hidden surveillance devices on their own inside a simulated living room, and then to do the same again using detection tools. The latter showed only a marginal improvement: participants missed 67% of the hidden devices when searching on their own, compared with a 59% miss rate when using a detector.

During the experiment, many participants reported difficulties in interpreting a detector’s readings. Other tools gave out false positives, causing anxiety in the participants, or missed surveillance objects entirely.

“Most of the detectors on the market are not designed with the typical consumer in mind,” said Polamarasetty. “Many people do not necessarily understand the limitations of such detectors and risk misinterpreting the results.”

He said many of the detection products were not built with at-risk users in mind, often emitting loud sounds that could alert the person spying on them. “They’re absolutely not safe to be used when you’re living with the perpetrator. The devices are not discreet enough.”

The researchers made several recommendations for manufacturers of detection devices, including making user guidance clearer and communicating inconclusive readings.

However, the authors noted these recommendations alone could not prevent tech-facilitated abuse, and the only real solution was to stop the sale of hidden spy devices.

The co-author Dr Leonie Tanczer said: “Most technology is dual-use, and companies have a responsibility to think about how their products can be misused – at the design stage, rather than after the harms emerge.

She added: “A camera in things like a showerhead or a plug – I just cannot really see a legitimate reason for that without the intention to monitor someone without their consent.”

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The UK domestic abuse charity Refuge said it had seen a “notable rise” in victims reporting finding hidden microphones or cameras inside their homes. Its policy manager, Bo Bottomley, said: “What is especially worrying is how accessible and affordable these devices are, allowing more perpetrators to weaponise them as a form of control.

“We urge the government to review how these products are designed, safety tested, marketed and sold, and to take swift regulatory action to mitigate the risk they pose to survivors,” Bottomley said.

Amazon declined to comment. A spokesperson from eBay said the platform “prohibits the sale of many products that are used to transmit or receive signals or for covert surveillance, and all sellers are required to comply with our policies and applicable UK law.

“After investigation, we’ve removed two of the three listings shared and we are committed to maintaining a safe and trusted marketplace for our buyers and sellers.”

A spokesperson for the Home Office said: “We will not tolerate covert filming or the harassment of victims.

“The government has committed to updating controlling and coercive behaviour guidance to reflect clearer recognition of technology-facilitated abuse and we’re making it an offence to take intimate images without consent, including by installing equipment such as cameras to enable people to do so.”

AliExpress has been contacted for comment.

In the UK, call the national domestic abuse helpline on 0808 2000 247, or visit Women’s Aid. In the US, the domestic violence hotline is 1-800-799-SAFE (7233). In Australia, the national family violence counselling service is on 1800 737 732. Other international helplines may be found via www.befrienders.org.