A man who is terrified of spiders found a poisonous black widow spider lurking in a bunch of red grapes he had bought from an Asda supermarket.
The black widow spider is found in several American states
David Humphrey, 55, from Rickmansworth, Hertfordshire, took the spider to a local pet store owner, Mark Amey, who confirmed it was a black widow spider.
Mr Amey said its poison would not kill a healthy person, but could be deadly for children and the elderly.
A spokesman for Asda said they were taking the complaint very seriously.
"We have someone on the case to find out what happened and Mr and Mrs Humphrey will receive a suitable gesture of goodwill from us."
The company transport their fruit over from America by boat.
'Terrified' of spiders
Their spokesperson said incidents of black widow spiders being found in fruit have occurred with all supermarket retailers, but it was extremely rare.
When Mr and Mrs Humphrey complained to the supermarket in Watford, all other bags of red grapes were immediately removed from the shelves.
Mr Humphrey said: "I am terrified of spiders, but my wife Joan is okay with them - she will usually scoop them up in her hands and put them out.
"But this one was different. It was very black and quite large."
The spider, which had red triangular markings, had spun a web among the grapes.
Mark Amey, of Amey Zoo pet shop in Bovingdon, said he would keep the spider in the store until it died.
He said black widow spiders only bite if provoked and they cannot be sold under the Wild Animals Act.