Writing on the Extreme Couponing and Bargains group on Facebook, the shopper wrote: "They sell all sorts in Home Bargains."
Alongside was a snap of the test kit, which promised 'next day results'.
"The fastest, most accurate home DNA paternity test in the UK is here provided by AlphaBiolabs, an accredited, award-winning UK laboratory," the product description explains.
"AlphaBiolabs uses the very latest DNA technology and is trusted by major media outlets. AlphaBiolabs is one of only a few testing laboratories accredited for DNA testing using up to 35 markers, giving the most accurate result possible.
"The DNA home paternity testing kit includes cheek swabs and consent forms, which must be signed and posted back to the laboratory."
And other social media users couldn't stop laughing at the £4.99 test.
One person commented: "Not sure I'd want to base such huge, potentially life changing information to a £4.99 bargain test."
"Potentially ruin your family by exposing someone's lie for just a fiver!" joked another.
And one added: "Ready for Father's Day!"
"Omg, I can see it now: Home Bargains £4.99 test said the kid's not mine!!!" said another.
And one wisecracked: "Now we will find out that you're the adopted one!"
Other eagle eyed shoppers pointed out that you still have to pay £99 to have the tests sent off to a lab - so perhaps not a mega bargain after all?!
"Exactly like the 99p Paternity tests, but the small print is you have to send of for it and it's like another £100," one pointed out.
And another added: "Not that cheap really is costs over £100 for the lab fees for the actual test."
The test is sold out online but looks like you can snap it up in store should you want one!
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