False widow
There have been a spate of attacks by steatoda nobilis in the UKWikipedia

A Welsh office worker had a fright when she opened a bag of grapes she'd bought at the Co-op supermarket in Cardiff Bay for lunch: two dangerous "false widow" spiders inside.

Nichole Sarra, 28, opened the bag at her desk and first was disappointed to find the contents consisted mainly of "dust and cobwebs" – then she saw something move.

As the first spider scuttled out, Nichole's fellow office workers corralled it and took pictures, identifying it online as a false widow. When Nichole sent a photo to the Co-op they put her in touch with customer services.

"I was told to go back to the grapes and get the barcode number for them so they could track it, they believed it came from Spain."

However when she inspected the bag again she found another spider dead inside.

false widow
A male Steatoda Nobilis 'False Widow' Spider in the wild.Getty

The British Arachnological Society confirmed the spider looked like a black widow but that the species is usually harmless, unless approached or handled, and that the female of the species is deadlier than the male.

"Only the females have been known to bite on rare occasions," said the Society.

False widows have been blamed for several nasty attacks in the UK, including one on Barry gardener Jason Butler, 41, who almost lost his leg after being attacked by five spiders in his shed. In 2013 William Fraser, 14, was bitten as he slept in bed in London and had to be treated with antibiotics.

False widows have been in the UK for over 100 years but the Natural History Museum stresses no-one has died from a false widow bite – and false widows often get the blame when other spiders have been falsely identified.

A spokesman for the Co-op said: "We are committed to working closely with farmers and suppliers in order to provide a consistently great shopping experience for our customers. We are sorry that this product fell short of those expectations and will investigate the matter with our supplier."