Asda Stores Ltd has been called out by consumer group Which? after it claimed one of the supermarket's sunscreen lotions offers less protection than it states.
In a spot check of 26 sunscreens Asda's own-branded sun lotion with an SPF of 30 was found to have failed both the initial test and a retest, Which? said.
An Asda spokesperson said: “We recently had our Asda Protect Moisturising Sun Lotion SPF 30 High retested by a leading external provider using internationally recognised testing methods.
"These test results confirmed that this product has a sun-protection factor of 31.5 - and therefore, we do not recognise the test results Which? has published."
Which? representative Natalie Hitchins claimed the findings were "incredibly concerning" that some sunscreens failed but claimed it was "great to see cheaper top-quality sunscreen options available on the High Street ."
Lidl, Boots and Aldi's products all passed the tests.