Concerns have been raised that the anti-vaccination movement is targeting children via Amazon warehouses, after a Hampshire mother found a leaflet condemning the HPV vaccine tucked inside a children’s book she had purchased from the online retailer.

Lucy Boyle bought Ali Sparkes’ Night Speakers along with several other novels as a birthday present for her 12-year-old son at the start of April. He began reading the novel last week, “got a few pages in, turned over the page and there was the leaflet,” she told the Guardian.

The leaflet warns readers that boys and girls are being offered the HPV vaccine in schools, stating that it is “causing injury, infertility, paralysis … ovarian failure and death, amongst other conditions”. The vaccine protects against human papillomavirus (HPV), which causes most strains of cervical cancer. Since routine HPV vaccination of 12- and 13-year-old girls was introduced in the UK in 2008, there has been a dramatic fall in the cervical disease that can lead to cancer.

Boyle said her son “came downstairs saying: ‘What is this, isn’t this the jab I’m going to have at school?’ He was worried as he had read the leaflet and knew he was going to have the jab.”

“I was just about to bin it when I thought: ‘Hold on a minute, that was quite targeted, it will have been put knowingly into a book read by 11- to 14-year-olds,’” she said. “That’s not targeting the parents, that’s targeting the children. It really left a bad taste in my mouth.”

She contacted both Amazon and the book’s publisher, Oxford University Press, eventually managing to speak to one of Amazon’s executive customer relations managers on the phone. He apologised, said the retailer would launch an investigation, and offered Boyle a gift card. In an email seen by the Guardian, an Amazon representative wrote to Boyle: “I am very sorry to hear about the negative experience you have had with the order for your son. Especially considering this was a children’s book and he is due to receive the vaccine soon.”

Boyle said the Amazon employee told her that though he had never heard of an anti-vaccine leaflet being slipped into a book before, workers had previously inserted notes on Amazon workers’ rights into titles. Two years ago, Metro reported that an Amazon worker was fired for sending a Jewish customer a note in her package reading “Greetings from Uncle Adolf”. In 2018, the Daily Mail spoke to a customer who reported finding a note in her delivery reading: “Please Help, Amazon is painful!”

On Monday, Amazon said it had checked all its facilities where the book was available, including where it was delivered from, and found no evidence that the leaflet was inserted at an Amazon site.

OUP also promised Boyle it would look into the situation, and stressed its belief that the leaflet was not inserted at its end, telling Boyle in an email that “this leaflet has not originated from OUP”, and that it considered the situation to be very serious.

A spokesperson for OUP said the leaflet was “not OUP promotional material, nor was its insertion authorised by us. Furthermore, our warehouse staff adhere to the highest levels of security such that they meet the standards set by the aviation industry. We are not aware of any other instances of external leaflets being inserted into our books.”

Boyle said she was concerned that both sides will end up blaming the other without identifying the source. “It may just be one leaflet in one book, or someone may have leafleted that whole batch of books … I don’t see what Amazon can do if a worker goes in with a bunch of leaflets. What’s the upshot, that every worker is monitored? That all gets a bit Big Brother,” she said.

Last month, a Guardian investigation revealed that Amazon appears to be helping anti-vaccine not-for-profit organisations in the US through the AmazonSmile Foundation, its charity arm. And in March, Adam Schiff, chair of the House intelligence committee, wrote to Amazon’s chief executive, Jeff Bezos, to express his concern that “Amazon is surfacing and recommending products and content that discourage parents from vaccinating their children”, citing a CNN Business report which found anti-vaccine books dominated Amazon search results for “vaccine”.