Carmelli Bakery has rebutted a claim that a cake from its Golders Green store made a customer violently ill for weeks.
A video sent to the JC by estate agent Stacey Fox shows a small white insect crawling around the remains of a chocolate rum ball, half of which she said her 18-year-old daughter, Jasmine, had consumed.
Ms Fox claimed that Jasmine, who has verbal dyspraxia and finds it difficult to talk, suffered diarrhoea and vomiting for three weeks afterwards.
"She took a bite of this dark chocolate and felt something moving, crawling. She looked and saw this creature nesting, coming out and back in." Subsequently, "she was very sick".
Ms Fox said the bakery had told her that the insects were psocids, also known as booklice. After the complaint, Carmelli removed the remaining two dozen rum balls from the batch from sale.
But it denies that the booklice could have caused food poisoning. The British Pest Control Association describes booklice as "harmless" and not a product of poor hygiene.
The owner, Janice Carmelli, said that "something from the same batch" had been sent for analysis. "They didn't find anything which would make someone ill. I saw the video, [pest-control company] Rentokil has seen the video and they said from what they've seen, it doesn't cause any harmful effects."
In a further statement, she wrote that "Ms Fox has neither provided proof of purchase to support this allegation nor has she provided us with the item itself".
Barnet Council's environmental health team has received a complaint over the matter and is investigating.
Nadina Mustafa, senior press officer at the Food Standards Agency, said
she was unaware "of any cases of booklice being associated with food poisoning in the UK".