A nut-lover devoured half a bag of Sainsbury's pistachios only to look down and make a stomach-churning discovery.
The horrified Whitstable resident found maggot-like navel orangeworms nesting inside and instantly felt ill as he realised what he had been eating.
He pulled open the packet of By Sainsbury's salted pistachios last Thursday as he relaxed at his Whitstable home.
While watching YouTube videos, he munched away on the snack which he had purchased from the chain's Chestfield supermarket.
"They are my favourite to eat, and never had an issue," he said.
"I got home and sat down to watch some of my favourite YouTubers, casually eating away happily distracted by what I was watching.
"Nearly half the packet was devoured before an ad break. I opened a few more, and then found a slightly discoloured shell.
"I was quite cautious about opening this pistachio, and to my horror, I found quite a few nesting dead bugs inside.
"I instantly felt unwell.
"I have never experienced this from the By Sainsbury's brand before and I was absolutely disgusted by the sight and thought that I had eaten quite a few before looking, not knowing if I had consumed more without my knowledge."
Sainsbury's has apologised for the sickening experience and says it is investigating with suppliers to determine how the bugs found their way into the salted nuts.
"I was absolutely disgusted by the sight..."
A spokesman said: “We have apologised to the customer for this experience and arranged a gesture of goodwill, which they have accepted.
"We have strict processes in place to stop this kind of thing from happening and we are investigating with our supplier. ”
Navel orangeworms are known to take up space inside shells and fruit, causing a nuisance for farmers and suppliers. They are fast-breeding insects which lay eggs on maturing nuts and hatch within 23 days.
If they survive to adulthood, they go on to become moths.
As well as nesting inside pistachios, the orangeworm also targets figs, pomegranates, and walnuts.