A £340 device which boasted it was able to protect people from the supposed negative health effects of 5G has been alleged to be a regular USB stick, worth around £5.
An investigation by the BBC claimed the 5GBioShield, which was recommended by one of Glastonbury Town Council's 5G Advisory Committee, appeared virtually identical to a USB key available from Chinese suppliers.
Ken Munro, from electronics testing firm Pen Test Partners, questioned what the difference was between the two, suggesting it might just be a sticker on the device claiming to protect from 5G.
"Now, we're not 5G quantum experts but said sticker looks remarkably like one available in sheets from stationery suppliers for less than a penny each," he told the BBC.
London Trading Standards was said to have since launched an investigation into the device.
BioShield did not immediately respond to requests for comment, although one of its directors told the BBC that they were "in possession of a great deal of technical information, with plenty of back-up historical research".
"It is hard to take your evaluation seriously, since you have evidently not researched the background facts in any meaningful way."
It comes amid growing concern over the number of products on sale making claims to shield consumers from 5G mobile signals.
5G technology is essentially just faster mobile data technology than the current 4G networks.
However, conspiracy theorists have claimed that 5G towers are causing coronavirus - something which has been shown to be entirely baseless.
Such claims resulted in attacks on a number of telecoms staff who were trying to maintain networks during the lockdown.
The US Federal Trade Commission has said there is “no scientific proof that so-called shields significantly reduce exposure from these electromagnetic emissions”.
In the UK, meanwhile, politicians have warned over the "dangerous nonsense" spreading on 5G over social media.
Julian Knight, the chair of the DCMS Committee, urged the Government to "work with social media companies to stamp out deliberate attempts to spread fear about Covid-19 and it is right that they are being called to account for allowing disinformation on their platforms".
Last month he said that, "to hear that crackpot theories are leading to people attacking phone masts or threatening telecom workers is sickening and it’s clearly time to act".
The Telegraph reported last week that items falsely claiming they can protect consumers from electromagnetic radiation and 5G, including underwear, stickers, blankets and a pill, have appeared on sale on Amazon.
The US company declined to comment.