Banned weapons such as folding knives, batons and axes on being sold on China-based website Temu for as little as £5, an investigation by Which? has found.
The consumer group says listings it found when searching through the site resembled items banned under UK law, while age-restricted products were bought without checks.
Researchers said several of the items were listed as “self-defence” items and “portable knives” and found by typing in “weapons”.
Which? wants Temu to improve its checking process, remove dangerous items and hold third-party sellers accountable where breaches are found.
Sue Davies, head of consumer protection, said: “Problems with dangerous products are only going to get worse if new tech giants like Temu continue to be held to weaker standards than high-street retailers.”
Temu has soared in popularity since it launched last September, with the interest driven by pop-up ads offering branded products at incredibly low prices.
In August, it was the most downloaded app in the UK for the year to date.