People should not use the Hightop HIV/Aids Home Test Kit, the medicines regulator has warned.
It has seized 114 of the kits, which could be giving out unreliable results, from two suppliers in the UK.
The Medicines and Healthcare products Regulatory Agency (MHRA) advises anyone who has used one in the past to get themselves tested again.
The tests did not have a valid CE mark, which means they have not met the required standard.
They were manufactured by Qingdao Hightop Biotech Co Ltd.
John Wilkinson, the director of devices at the MHRA, said: “People who buy a self-test kit online or from the High Street should know what they are buying is safe and reliable.
“Make sure the kit has a CE mark and clearly states that it is intended for home self-testing.
“If you are concerned you may have used an unreliable test kit, speak to your GP, sexual health clinic, pharmacist or other healthcare professional.”
Cary James, from the Terrence Higgins Trust, said: “Home self-test kits for HIV and STIs [sexually transmitted infections] have many benefits, including letting people test in their own space, in their own time, on their terms.
“However, we are extremely concerned to see unregulated produce on the market and urge anyone considering a test to only use those with a CE mark.
“Anyone taking a test without a CE mark risks their own health and that of others.”